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.
Changing a supreme commander every 1.5-2 turned out to be a good practice during WWII for a good reason. Every general has a limited supply of new tricks, you need to periodically rotate a fresh one in