The problem is not really grens but rather a combination of buffs to allied units and nerfs to ost units. Grens are meant to be used to support mg, sniper, lvs until tanks arrive. Problem is allies can now exert to much pressure and grens cannot hold ground to provide support to other units.
The problem has risen slowly due to "balance experts" slowly buffing every allied unit that was deemed to be under performing which when looked at in isolation is not an issue but when combine with other buffs simply add up to an insurmountable wall.
I don't think the issue would be so bad if Ost tanks weren't nerfed as much as they have been, The nerfs to to stug are over the top, the Ostwind still sucks, the P4 could really have its moving accuracy buffed and Tiger and T4 units need a buff to their armour so that they can actually push forward when allies are camping.
The other issue is grens do not perform at all well when the allied player invests in indirect fire and unfortunately USf has indirect fire in spades. Grens generally have to remain stationary when engaging the enemy but as soon as they get hit they instantly forfeit the engagement and have to retreat or risk getting wiped. Allies on the other hand ( who also have larger squads generally ) can keep moving when under fire from indirect. To add insult to injury is the fact that ost will rarely be able to wipe the allied indirect units unless they go afk.
I don't mind units dealing high damage if they can be countered with reasonable effort but that is just not the case with allied indirect fire.
I find the amount of indirect fire so bad now that almost every game vs Usf requires me to get the command panzer just try and keep units alive while being constantly barraged to death.
The other issue that bugs the shit out of me is how units will almost always take damage from grenades if you try to move out of the way. This because the changes to spacing cause 1 unit to stay anchored in place while the rest of the squad moves. So when my opponent throws a grenade and I am madly clicking like a "fucking lunatic" trying to get my squad to move, I often still take massive damage, all because the squad wont respond. Small change but contributes to the problem.
I don't think there is a simple solution Tbh because this has come about slowly through numerous small changes.
Edit : IS lategame OPAF