Even though the meta has not settled yet, ostruppen doctrine is one of the top contenders for meta doctrine of new patch. What OP suggests is changing them so that they can counter a build that is currently their counter build. Which would make the doctrine even more dominant.
You have a fair point in that Ostruppen doc is popular, however you have to realize that Hit the Dirt is a cost-free counter to a unit that requires numerous squads to become effective.
A 600MP + 135MU investment should not be easily countered by a 340(or was it 360?)MP unit with a 90MU upgrade using a completely free ability.
Despite the pluses of having a grenade ability and the removal of their no-cover penalties, they are still cheap infantry with positive received accuracy modifiers. On the approach, they're far more vulnerable than pioneers with only a bit more DPS. If they are used defensively from long range, they would be outgunned as their SMGs are only effective at close range.
They would be extremely situational as the attrition rate would negate less-than-ideal tactics, and an over-reliance on grenades to compensate would starve the player of munitions.
Considering that volks armed with MP40s also share a similar crisis of MP40s or STGs, it could be used as a bit of a case study- But on far more inferior infantry with less utility.