No, OKW have MP float, because they don't have nearly as much attrition as any other army as their infantry scales defensively to the level of being overpowered compared to any other infantry survival in game.
You know there is something wrong when cheapest main line infantry got as much survivability as doctrinal specialized close range squad once it gets few vet stars.
Moreover OPsoldaten only widen the attrition gap because unless you blow then up with tanks, they will cause much more mp attrition then they will take, widening the MP difference even more.
None of the infantry vet scaling makes them take less damage from indirect fire. And the reason you have very little MP drain is because they don't have units that cost lots of MP, the most expensive MP only infantry unit is Obers (Not counting the ISG because who the fuck does). Volks are cheap and plentiful, but most of the time If I can get something else I do because relying on Volks isn't a good idea when your facing Shocks and Paras.
If OKW vehicles cost a lot more MP, then the OKW player spent the MP they would be getting less income due to filling up their popcap, meaning they would be hard pressed to replace losses (which is how OKW is supposed to work) due to reduced MP and fuel income.
For example if the Panther cost 800 MP but 140 fuel, I very much doubt you would see more Panthers, but I can assure you that you will see less infantry spam.