Rifles either start with veterancy commander,going to vet far sooner than grens.
Or get 1919 which will laugh at grenadiers even with lmgs.
Or get paras which will again laugh at grens while reinforcing at 28 mp kappa.
Not even bringing in light vehicle,or us one shotting options like motor/pack howie and sherman which ost don't have access to till tiger(which still can't one shot unless freak)
Just no. Go play some 1v1s and show many how many times EVEN with Elite Rifles the US player beats Grens to Vet 3. You wont see many. Because as I said Vet 2 doesnt help propel them to Vet 3. It just makes them easier to keep alive. BARs arent as drastic at a DPS change as LMGs are. And with the XP pool of rifles being bigger.
In fact I would venture a bet that Infantry Company Rifles with LMGs will probably get to Vet 3 faster then Elite Rifles with BARs...
You point out Legit problems with the faction as a whole:
Tech too expensive
MG42 lackluster
Early USF light vehicles
Free Officers (initially but hey they cost you in the long run)
But your answer is to buff Grens? Thats like saying OMG BUFF CONSCRIPTS BECAUSE OBERS!!!
Grens do not struggle nearly as hard against Rifles as Rifles have to struggle against Obers or Falls. And yet USF can beat OKW.
So I think your expectation would be Grens to be equal to more expensive Riflemen? Poor Conscripts being just completely clowned not just out-scaled like crazy.
That doesn't sound too reasonable. You are treating a symptom and not the problem.
If you could get out a P4 or Ostwind or Stug faster and for less and the Jackson didnt just plain erase them, then you can support Grens. If the MG42 worked better then Infantry Spam could more easily punished. But reading your arguements it seems you want all of the above which would IMHO make Ost rather OP.