In the Western doctrine of the military, there is a set of axioms known as “the Principles of War.” They are different between nations. In the US military, they include the following types: Objective, Offensive, Mass, Economy of Force, Maneuver, Unity of Command, Security, Surprise and Simplicity.
They are generally self-evident; however, unless a conscious effort is put into adhering to them, they will be breached, with often dire outcomes. For example, the goat rope of 20 years ago used during the war in Afghanistan was the direct and obvious consequence of not being able to establish an objective that the use of military force might have accomplished.
The Russians seem to have made a point of breaking all of these rules, excluding offensive and objective. Their numerical advantage was blown away when they attacked on four axes (Belarus/Kyiv, Kharkhiv, Donbas, Crimea-Kherson), which meant they could not be forces for each other. Terrain combined with inexperience in forming single-file positions. Russian officers discussed battle plans over unsecure telephone lines. The strategy was extremely complex and based on the notion that the bulk of the people in the Ukrainian Army would not fight.
The main failure, however, was the inability to attain Unity of Command. In the first phase of the war, up to three generals were in charge of the battle on the ground. It is not surprising to discover that there was a distinction between the Russian Air Force and Navy; each had its own commanders. In the end, the Russians were the most powerful force, but that standing was not utilized to gain the advantages they had.
In the beginning of April, Russian President Vladimir Putin attempted to remedy the issues with the command by appointing the head of the Russian Southern Military District, General Aleksandr Dvornikov, as commander of the whole “special military operation.” The decision to appoint Dvornikov was for three apparent reasons. He was, firstly, the highest ranking of the generals who were involved in the mission, although it was widely believed that this position belonged to the Chief of General Staff of the Russian Armed Forces and First Deputy Defence Minister, Valery Gerasimov. This would prevent any disputes regarding seniority. In addition, Dvornikov commanded the Russian troops in Syria and was renowned for allowing casual brutality by the Russians stationed there, as well as bringing different military factions who had been operating on their own under his direction. In the end, the offensive actions of the Southern Military District were viewed as the most effective in Putin's War in Ukraine.
Three weeks into his tenure, it's certain that Gerasimov isn't Georgy Zhukov’s successor or Alexander Vasilevsky’s. The Russian Army has not yet solved the issue of concentrating their ever-increasingly battered troops in one particular zone. There are too few soldiers and too many tasks to complete. Time is short for the Russian Army because it is becoming more and more apparent that the Ukrainian Army is growing more capable and better equipped every day. There are rumors of a significant change regarding the military administration during Putin's War and the structure of the command on the field. The most popular rumor is that Russian President Vladimir Putin is taking over the strategic direction of the conflict.
It’s not certain that anyone other than the Kremlin could confirm the truth of this, however. The war is not just a Tartar slave raid; it's a war that will significantly determine the future of Russia. This war will influence Vladimir Putin's destiny because he has constructed the image of a man who can restore Russia to its glory days. The implications of economics and politics are quickly eclipsing the military, and as the head of the nation, he needs to assume the helm. He shouldn't be perceived as losing in Ukraine, but his ego believes that his country will win if he gives his complete focus to the conflict.
Another likely alteration is that Valery Gerasimov, the Chief of the General Staff for the Russian Armed Forces and First Deputy Defence Minister, is now in charge of taking personal control of the conflict. There is no confirmation of whether this means that the “Butcher of Syria” Dvornikov was relieved and has been appointed assistant to Gerasimov or is in control, with Gerasimov “boss monitoring” the entire operation from afar. In addition, no one knows what this means for the future.
Retired Australian Major General Mick Ryan provided this analysis:
1/20 It's been just 64 days since Russia’s invasion of Ukraine began. Today, we will look at the consequences of Gerasimov “taking over” his role in the Russian military invasion in Ukraine.
2/20 There are no confirmed reports that General Gerasimov has relocated to Ukraine and could be being given the overall command in this Russian campaign. It's still being considered a matter of speculation. This thread should be used as an idea experiment.
3/20 General Gerasimov is the head of the General Staff of the Russian Armed Forces. The position was entrusted to him by… Russian President Putin on November 12, 2012.
4/20 What is the reason why the top Russian military commander is in charge of what is really theater command? If this is confirmed, it will be a major intervention likely controlled by Putin and could result in an alteration in the way Russian actions are planned and conducted.
5/20 It's not common for the top army leader in a country to take a step down to take on an operational position. It's a sign Putin is not having enough alternatives in the Ukraine specific operation. There are some intriguing operational and strategic implications.
6/20 Strategic effects. Who will succeed him? Gerasimov has been the leader of the Russian military in its reforms over the last decade. Gerasimov also oversees the day-to-day operations of the entire army, including the strategic forces. It's not a post that should be vacant for any length of time.
7/20 Gerasimov moves to Ukraine. If no one is able to replace Gerasimov, who will supervise all Russian military operations and development in the short [term] and any mobilization?
8/20 Is it a sign that Russian military strategy is improving–or even worsen[ing]? Despite the legend of Gerasimov prior to the war, his performance as commander of the Russian army he supervises from strategic to tactical has been a bit subpar.
9/20. Not only is it ineffective when it comes to combat, also the atrocities it has… committed–destruction of cities targeted, killing of innocent civilians, and murder are a sign of the corrupt professional ethics. Gerasimov is ultimately accountable for this.
10/20 Lastly, what does this say about the mindset of Putin? Did he lose confidence in Gerasimov?
11/20 In WW2, General MacArthur appointed US Army General Robert Eichelberger to command US forces at Buna. Before leaving, Eichelberger was told, “Bob, I want you to take Buna, or not come back alive.” Did Gerasimov receive a similar order from Putin?
12/20 Has Putin and Defense Minister Shoigu put in place Gerasimov as the main “blamer” for any Russian error in the war?
13/20 Operational effects. If Gerasimov's appointment is confirmed to [make] General Dvornikov's job…different.. Maybe Gerasimov could be the joint commander overall, with Dvornikov being the commander of the land component.
14/20 Maybe General Dvornikov hasn't proved to be [the] effective joint commander that the Russians wanted or not been able to meet the timeframes of success for strategic planning.
15/20 Gerasimov is well known for his work as an expert on military theory. Although his theories have not yet [been] tested on the battlefields of Ukraine, …Gerasimov might be able to bring a better quality of joint planning in execution and planning to Russian operations. This is a very good possibility.
16/20 In order to accomplish that, Gerasimov would need a joint planning team. He'll need more than just a couple of command vehicles as well as an aide-de-camp and a safe satellite phone for him to be able to exercise actual authority to command Russian actions in Ukraine.
17/20 The most effective generals can typically be found in just one or two locations on the battlefield, namely at the area of the greatest risk[s] and also the area of greatest opportunities. They do this because they are able to best manage resources to assist their commanders on [the] ground as well as to lead the troops.
18/20 Gerasimov will be heading to the Russian Army's area where there is the greatest danger and chance. The most risky, as losing in the eastern region could trigger an extended pause in the operations and force the Russians to replenish their forces and think about their strategies. This could have a negative political impact on Putin.
19/20 It's the best place to be because it's probably the only place in which Russia is likely to achieve an operation-related breakthrough, which will enable them to inform the people of their country (and their international partners) they were successful in Ukraine. [The] Russian military has been success[ful] in Ukraine.
20/20 Gerasimov, up until recently, was considered to be one of the best Russian thinkers of [the] contemporary period. But his reforms haven't been a success on the battlefield. It's unlikely that being on the field, [in] the command of… tactically weak Russian forces, will affect the situation.
Professor of political science and a fixture on the GOP Establishment’s foreign policy, Eliot Cohen has some details about what the decision will mean in terms of political implications:
If it's true that General Gerasimov has assumed direct command on combat missions in Ukraine from a forward headquarters, there are as usual two possible scenarios. 1/6
The second is that, as the Russians begin the most decisive maneuver(s) of [the] conflict, they'll need their top field commander to accomplish the heroic task of managing fire and maneuvers as well as sea and land like a top field commander could. Naturally, he's also the most effective! 2/6
Another possibility is that this isn't the personification of Suvorov, Zhukov, etc. But he has held the top position for over 10 years. Things aren't going well. Perhaps extremely horribly. It could be quite severely. 3/6
It is not fair to blame the Boss for launching this absurd war that could leave Russia weak, isolated, with a bigger and stronger NATO right at their doorstep, especially if they fall victim to the Ukrainian peasants! 4/6
Then you send your Chief of General Staff to the front with the message: “Fix this or don't come home.” This leaves you with a great individual to take the blame (nobody knows anything about Dvornikov in the first place). At this point, you're not concerned about a general who is successful in launching an attack. 5/6
…because this might be a massive catastrophe. This is why you'll need an effective excuse for the situation. Truth may be somewhere in the middle; however, I'm betting on the second. There is no reason to believe Gerasimov is, in reality, likely to be an experienced theater commander. There are also issues that as @WarintheFuture has pointed out. 6/6
Both stories are not confirmed at the time of writing. Both accounts are plausible in light of the military and political mess Putin's War has turned into. The two theories aren't a reflection of confidence in his leadership.