Changing a supreme commander every 1.5-2 years turned out to be a good practice during WWII for a reason. Every general has a limited supply of new tricks, you need to periodically rotate a fresh one in
Dude was in charge of the defense of Kyiv early in the war, and of the counteroffensive in the North that succeeded so well everyone forgot there was ever a northern front line inside of Ukraine. That’s one hell of a resume man.