Just tone down penetration on the M5 so it wont tear apart 222s. it's only OP against light vehicles, versus infantry its the only thing soviets have that kills infantry quickly
That isn't even near true. The Soviets have tons of options to kill infantry quickly. From Shocktroops, and Guards, to mortars, the maxim slays pretty quickly, Penals can be brutal until encountering assault rifle wielding units and elite troops. The T-70 is an infantry slayer.
T-34/76 and 85 crush and kill infantry moderately fast.
The Soviets also have the Katyusha and tons of artillery options to kill infantry quickly. The M5 quad-mount as it is, is unforgivable. So don't even try to use the lame excuse that the Soviets are so desperate to kill infantry that they need something as ludicrous as the M5 Halftrack as it is.