Osttruppen are only efficient in singular engagements against other mainlines, camping behind cover to wear them out before slowly advancing. Teamgames usually resolve more around assaults, massed engagements, HMGs, indirect fire and elite infantry. They are terrible in those situations.
That's a good point.
One slightly odd thing is that they generate quite some over-accuracy, which means that compared to Grens a vetted Osttruppen performs better against low RA squads (either a highly vetted enemy squad or the enemy squad is in cover) than against a high RA squad like a newly build one or in red cover. It is only a minor thing but still strange behaviour.
In my calculations, I also saw that the "new" Osttruppen squad as in the preview beats late game Grenadiers in terms of firepower per population and even more so in MP efficiency. In live, Osttruppen are equal to slightly worse. The LMG buff will buff late game Osttruppen out of cover almost to the level of current Osttruppen in cover. New Osttruppen will beat Grenadiers in most situations.
These calcs are the most meaningful for dragged out squad vs squad fights, which are more prevalent in 1v1. The current buff will therefore be mostly for 1v1, I though you were trying to target larger team games as well?