In my opinion the Sturmtiger is fine. Good at clearing AT guns and other support weapons, but not so much against more mobile infantry.
I don't know why people want the ST to be a mobile B4 that only fires precision shots, with a tenth of the projectile travel time of the B4, and with just enough range to stay out of LOS so the enemy won't see it comming. You think that's a good idea to balance a game?
As I stated in the opening post. If it does not get more range then it can not perform unless the opponent makes a mistake. Even support weapons have enough time to react. And an end of doctrine, sexpensive unit only for having a chance of killing support weapons is bad.
A higher rate of fire will not fix the Sturmtiger. That only leads to it not being able to hit more often.
Nobody wants it to fire "precision shots". As already stated I suggested to decrease the accuracy if it is ever going to be a piece of artillery.