Expensive yes, but those units can take an incredible amount of damage and still survive, then no need for them to build more, which mean more ammo and fuel are not needed.
Also, how can a faction have the most survivable units AND the most potent vets as well? The combination is just stupid.
Yeah but I'm speaking in 1v1, I love OKW and in 4v4 is too OP I know, but 1v1 vs USF can't do any with no panzerfaust and vs SOV is just conscript spam and wait for IS-2 or T-34/85