Honestly the only thing allies need are reliable AT. At the moment USF and Soviets got no reliable AT. If they don't rush TDs. They are going to lose because AT guns are not reliable against anything above a panther. Now people may argue we'll you need more than one, but then no only did you sacrifice field power by not having enough infantry to deal with been and volk blobs. Which will eventual be your demise
it's not like getting a 2nd at gun late game will instantly make you lose all or most inf battles