The conscript/grenadier balance is fine... what makes ost difficult is the lack of a "penal battalion" analog that allows it to crutch against rifles... the real solution here isnt to buff grens but to re nerf rifles and penals
You do that and then again OKW will stomp these two.
The solution isn't to buff or nerf anything, the solution, for ost, is to stop pretending they are OKW and use team weapons and/or snipers.