I would guess that's just about exactly what they will use them for. They probably have very little ammunition they could trust for the smaller guns. Give them each a round or two and send them in. When they get to PBR try the gun. If it goes off even if it doesn't work well or hit anything, it still has to draw return fire. One less 300,000 dollar missile for tanks that are more likely to work. They can probably accomplish that mission with a one or two man crew. and Russia seems to be inclined toward expendable bodies so only one or two is better than a squad or a full tank crew.