The problem ultimately stems down to the fact is that you can't give a faction a very narrow selection of units on top of a resource penalty and hope that through the power of magic dust and fairies people aren't just going to spam like motherfuckers.
Narrow?
OKW have as wide selection as any other army, even wider as they have only 2 extremely situational units while other armies have plain useless ones.
Also, for a resource starved army, for some reason they can pump fastest armor in game with fastest tiering and additional bonuses cost-free for setting up said tiers while other factions need to pay for their utility additional costs. Doesn't sound too resource starved to me.