OKW guys tend to be more atacking than defence , they like rush to a certain point , very deep in the map in most cases
This is how you're supposed to play OKW.
than ofc he gets overextended and have to flee once enemy counter attacks , than the territory they gain goes to nothing and the others just defend because more easily in the counter attack that follows .
This is the difference between a good OKW player and a bad OKW player.
OKW can be a support army , but people tend to use them like a one man army and neglect flanks and or the rear of friendly armies .
The only "support" parts of OKW are the JPIV, KT, and Stuka. Otherwise OKW is a very aggressive army, although they should be flanking, not attacking head on (that's Ost's job).