I'm no pro, but I think that your first thought to avoid a squad wipe from a HARD COUNTER to infantry would be to retreat your squad(s) away and bring them back with something that COUNTERS the Scott. It's not like this thing does show up on your map or even in the fog of war once its fired. I don't run riflemen and paratroopers into a sturmtiger, I retreat them. Hell, I don't typically run infantry into a vehicle designed to kill them effectively(ex: aa halftracks/luchs etc.)
This vehicle isn't that OP, is it powerful, yes, but it's powerful against exactly what it was designed for, uber-vetted axis infantry.
Dude, Sturmtiger have a very high aiming time and travelling time of the rocket itself, it's range is similar to your troop LOS so you have a long time react to it, and retreat.
Scott is another issue, it's range > infantry LOS.
Just giving a scenario, a squad of Volks sticked to the green cover, due to the stupid system we have now, they stick together.
Scott can one shot wiping the Volks (direct fire, not barrage), axis player have NO WARNING, nor even know the Scott is here, and he lose the whole squad.
That's what the problem.