You are confusing consistency and faction design. Each faction has its own trademark and OKW being able to built outside their base is one of their trademarks.
If OKW losing a T4 should deny their Tiger, then USF Major who comes with allot of utility should have an added 90 fuel cost and be required to be alive to call-in a Pershing...
Bottom line is that requiring T4 to call-in a JT or Tiger does not have to with balancing OKW that still have access to KT but has to do with the respective commanders and denying access to this units is not a good way to balance these commanders.
USF's trademark is it's tech giving you a "free" squad, which in this case is the major. Why can you use the trademark for OKW defending points but not for USF getting a squad?
BTW major's "a lot of utility" is not worth the fuel.
Also, whats easier to keep alive, a 3man squad or a building?
If you want to stall for very heavy doctrinal tanks, why should you also be allowed to take early game benefits (putting trucks far forward) without risking being punished for it? If your commander has lategame vehicles, why shouldn't you play like you are playing for the lategame?