They're missing 3v3 style PGrens blobs A-walking into everyone and everything. Destroying tanks, support weapons and infantry alike.
That actually never happened without serious casualities and amo investment, for the simple reason a schreck upgrade is 120 amo. 2 upgrades - 240. And so on. The bigger the "blob" the smallest the chance to have amo for anything else. More than this, even before T34s for instance (if we are talking about tanks) tore them to shreds. Or you could stop the infamous blob easily with 2 maxims.
Anyway, before the patch they were niche units - without schrecks good against T1 and conscripts infantry units and with schrecks good against Su-85s and any tipe of vehicle except vehicles with high damage against infantry.
Now, I'm really trying to find a purpose for them (when not schreck upgraded), except staying in green cover and watch a mortar or mgs back. For such purposes a 200 mp unit should do the trick, not a 340 mp one.