These guys are going to leave via S'n'T if they do leave. LeBron or Wade or whoever is not going to leave that extra year of $20 million sitting on the table and his former team out to dry. At that point, if you're the Cavs or Heat, you go with the best S'n'T offer. If Dallas' offer trumps what Chicago or New York is offering, LeBron wants to go there, and you have no shot at retaining LeBron, why wouldn't you trade him to Dallas?
I never said it was anything more than a remote, remote possibility LeBron would come to Dallas.