Thanks for your Advice !
So we should try to rush them with our UC's so they get early behind but from the momentum when the volksgrenadeers have the fausting abilty the UC's seem to be useless should we throw them from then on now ?
The UC is actually not that hard to keep alive when he has fausts (as long as you don’t get the freaking wasp). You just need to make sure to stay at max range and you’ll be well out of the range of fausts, especially okw (volksgrenadier) fausts since IIRC they have a shorter range than ost (grenadier) fausts. The UC also does more damage at max range, so there’s never any reason to close anyway. Like rosbone said, you should always be kiting his infantry, which is probably just something you may need to practice more. The vickers K (machinegun) upgrade for the UC is also usually much better than the wasp (flamethrower) upgrade, since the flamethrower has a shorter range and thus harder to keep alive.
As for the other stuff just make sure you are aware of the field (also takes practice) and know if and when a flank is coming, and reposition your mgs to cover it. Your infantry sections can usually beat early okw infantry 1 on 1 pretty reliably and the vickers should help a lot as long as you keep them firing. Keeping the vickers in key buildings can be helpful too, since they can face other directions a bit faster in buildings and have better cover, but you need to watch for flamenades and be aware that some buildings don’t have windows on some sides or the windows are blocked by something like a hedgerow.
Commandos are really good in the midgame but take a fair bit of micro and practice to be used really effectively, but they are a potential solution if you're still having trouble with his infantry.