When I talk about garrison it is not a pure balance issue but map/balance issue. Some maps have vital houses some do not.
(late game performance of OKW is rather irrelevant here since we are talking about map related issues)
Having a Maxim that is too strong when in garrison will make Soviet (or Soviet T2) a very map depended faction, and that is bad design.
As I said before in my opinion Maxim is too strong when in garrison and changes should be made to either nerf the maxim when in garrison or buff the tools available to axis to deal with it.
The maxim is no stronger in garrison than any other MG. You just want to keep maxim weak. You're not accepting that Relic has imposed strict scope changes so Soviets need help from their maxims (currently).