Honestly, I can't see how they gain anything from deferring to him at all. He has shown no a near-total distaste and indifference to European issues, it seems like the Russians will get everything they want that he could do for them by just ignoring him, because whether they give him an inch or not, he's going to do all those things (strategic disarmament, disengagement from Eurpope, cessation of support for any former Soviet republics or Pact nations) anyway. Perhaps they'll be nice to him just to be contrarian, but it doesn't mean they'll agree or deliver on anything that isn't clearly to their advantage.