Hmm not really, since you only need 1 Tier structure to build without a BP upgrade. As Ostheer you've to get 2x a BP upgrade and a tier structure.
Road to unlock P4
With current 105 schwerer cost:
Wehrmacht
80/10 for Tier1 building
100/40 for BP1
200/20 for Tier2 building
100/45 for BP2
260/75 for Tier3 building
--
170 fuel - 20 starting fuel =
150 with all tier buildings (ofc u can skip tier2 or tier1)
OKW current preview mod
100/15 SWS truck
200/25 (battlegroup) or 200/50 (mechanize)
100/15 SWS truck 2
200/105 schwerer
--
a) cheapest way 160 fuel - 10 starting fuel = 150 fuel
b) with mechanize instead of battlegroup = 175 fuel
c) all trucks = 215 fuel
If we increase schwerer fuel by 15 fuel
a) cheapest way 175 fuel - 10 starting fuel = 165 fuel
b) with mechanize instead of battlegroup = 190 fuel
c) all trucks = 230 fuel
So if we increase the price of schwerer, going fastest route OKW p4 will still come later than Ostheer with all tiers. Then again OKW panther still will come way faster than ostheer one, and also u get all the cool featuers of OKW trucks - but i think late ostheer panther is a problem of ostheer T4 teching..
Maybe put upgrade on schwerer that will unlock panther/kt and gun on flak?
OKW P4 is better then the ostheer P4, why should it come out at the same time?
It also cost more.