Wagner and Russia in the Battle of Rostov

There are two sources of troops for Wagner, the military veterans and also convicts that they've pulled out of prison to use as cannon fodder. So Wagner absolutely has no staying power in this fight. The question is what can they do in the very, very, very short term? They have access to the military stocks around Rostov, and that's it. I would expect them to win and win handily, but Russia will not recover from that sort of image.