I like the disability.
OKW is loaded with elite infantry, elite abilities, and elite armor units.
However, to me the design problem is not the economy. It's impractical vehicle units. The Luchs, rocket HT, Sturmtiger, King Tiger, IR halftrack, and JagdTiger are rarely built.
Only the 20mm HT, Puma, Jagdpanzer IV, and Panther are built on a regular basis.
Also, the infantry gun doesn't see much action. So OKW is much about elite infantry.
Come to think of it, I really should build the IR halftrack more.
All of these are more visible in teamgames. The luchs may be quirky for its cost, but I have faced it a lot. Ir half track - map hax. Infantry gun, devastates blobs of infantry and at guns. Walking Stuka, very usefull for wiping defensive positions or blobs, especially on chokier points. Jagdtiger, might be hard to get to if you build vehicles and forget to salvage stuff. But placed well, it's a pak43 on tracks. Amazing how fast it deals with armor. KT, agree with you there, don't see it a lot, but it's not like it's never built.
On topic, the teching as suggested earlier int the thread is one very important aspect. Teching is silly cheap. They also have a lot of boom for the buck. If resources would be equal, the cost of the units would need to go up. This would also hurt, especially if manpower cost is increased.