Don't know about WWII in general or the eastern front specifically, but its SOP in the IDF for an HQ tank crew to switch tanks with another crew if their tank became immobile or destroyed. There was a lot of that happening in '73.
It also only makes sense that if, for example, there are 2 tanks- tank 1 destroyed and crew bailed out and survived and tank 2 had its crew dismounted but killed, that crew 1 could mount and operate tank 2.
I also can't see why different crews can't operate a tank that had some of its crew members killed to a point where it is now immobile/unable to fire.
Non of the above is ideal by far, but not only is it good sense, its also done in combat (again, don't know about the east front, more about later years over here).