Kofman criticized him for a number of things, including going on offensives at times when held have benefitted from being on defense.
He's not being replaced by someone with military expertise, though, so I'm not sure that that's the driving factor here.
And his own background was in disaster response. I don't know how much of the actions taken under him were, in fact, from him. Kofman had to be guessing, to a certain extent.
In Britain, they compare the length of your term with how long it takes lettuce to decompose. They don't bother in Russia because it's always the lettuce.