You see this thinking in science too. Dark matter has always struck me as an awful solution to a model breaking down. It’s basically “the numbers don’t add up so let’s add a fudge factor to make it say what we want”. But you’re generally considered a kook for questioning it now. People will spout a bunch of big words and hope you shut up if you do.
Why would sa make a deal with him? It would have to be secret and there’s zero chance he would abide by it later. If he wins and they kill him its a war. If he loses they’ve bought nothing anyway…