Advice to Urkaine from a Middle Aged American male who never served in the military and watches WW2 Docs.
It has been said that defense has a 3:1 advantage over offense in terms of soldiers i.e., it takes three advancing soldiers to take out one soldier hunkered down.
Russia is currently dragooning soldiers who do not want to fight, and will suck at being solders, but who knows, Russia may pull a "retreat and your family will be shot."
So, Ukraine, get as much territory NOW before even those crappy soldiers get to the front.