The problem here is you then break the early Conscript vs Grenadier match up. Grens do fairly well vs them early game, with Cons only winning if they have better cover or coming around the corner.
Which leads to, how do you buff Grenadiers without impacting a lot of other areas..
And that is why it not grenadiers that need to be buffed but the allied game play that need to be toned down.
Having that said grenadier vet 1 ability is bad so it should be replaced, maybe a he grenade to offer some protection from charging troops?
Or/and moving some received accuracy earlier and some of accuracy later in the vet bonuses?