If anything, I would prefer changes to T70 and Su76 instead, rather than swapping them.
T70 went through a very problematic period. As a light tank, it was always wierdly aligned to begin with. SU76 is also a wierd unit to begin with.
Primarily, imo, SU76 barrage combination with ZiS barrage, at that stage, would be absolutely devastating to infantry/support, as a result of the sum total of indirect fire. But, in addition to that, both of these units also function as native AT, again, at a relatively early tier. This combined AT/AI potential frankly scares the hell out of me.
SU85/T70 combo I find less concerning, but I defer to the judgement of those here who see that also as extremely problematic. My rrsistance to that part of the change, is a different one. I think it squeezes T70 out of its already marginal optimum. T70 balance is hairline thin, as it is. I, for one, think T70 and SU85 combo is not something I would want, and which weakens Sovs T4 substantially, especially in favor of a Support/SU76 lineup.
I foresee very problematic unit combinations coming out of a T70/SU76 swap.
Swapping t70 and su76 doesnt make su76 come earlier like you seem to think since both buildings are the same price.
Su85/T70 combo isn't a issu at all since the su85 already have 2 ways to increase vision and you should generally have infantry or something in front of you su85 to spot
+IMO T70 is crap since the release of WFA(especially in team games), it comes too late and it doesnt have enough hp. 320 compared to 400 for the panzerII that cost 20 less gas while germans already have way better AT capacities... a puma can come into play around 5 minutes or more before a t70 can come in, even with soviet industry. For 70 gas, I think it s too fragile. I mean I already killed a t70 with 2 upgraded 222s. It basically gets 2 shotted by AT guns or medium tanks and 3 shotted by panzershreks. If your ennemy has one squad with shrek(s), you can't even think about engaging and you pretty much have 1 minute to use it before a panzerIV is on the field.
Also, maybe it s not the right place but wtf with faust ability that triggers even if the targetted unit is further then the circle area and never came in. Faust already has the most range of all AT nades... it makes it even harder to micro a t70 against wermacht and with the nerfs to the M3 acceleration and decceleration, M3 is just impossible to micro against wermacht. Before you wanted to stay at far-midrange to deal damage to grenadiers and now you have to stay at almost max range all the time and since grenadiers have decent dps at long range, most of the times, your scout car (with penal) doesn't last long enough to even kill a squad 1v1. FIX the faust!! plz it cost the same as other AT nades, has better penetration, longer range, but doesnt need teching, veterancy or a call-in unit (like OKW)... So at least make its range be as intended not further