The 105's a Brummbar. If it's not pulling its anti-infantry weight relative to a regular HE Sherman then it needs further buffs, not replacement in my mind.
The unit's conceptually sound.
It doesn't have the durability to do what the StuPa does, it lacks the armor and health to do those frontal assaults, while it has smoke canisters as any other American Sherman does and could benefit greatly from the new Elite Vehicle Crews. I still haven't seen a situation the cheaper baseline option isn't just better overall.