You bring up a really, really good point. In this bizarro world, I'm actually rooting for the Russians. But they have not been very successful in the past. Will their latest adventure be any different?
They are simply there to keep their ally Syria from falling. The Russians are not good at strategy in advancing their interests. In this case, let them fight ISIS to their loss if they lose, and the Wests gain if they win, with one caveat, this will not end well for them either way. Let them spend their resources, not ours, but then again, this could be only a temporary measure, they will leave when their losses mount, they are already in poor economic straights. See Ezekiel and Revelation.
Russian military will have learned lessons in Chechnya and will not lose to irregulars again.