Agree with Core4 here. It is (or should be) about team building. Sure, Lebron can probably strong-arm his way into playing with more big names in Miami, or elsewhere. But after what San Antonio did to him, you'd think he'd have constructing a great team on his mind a bit more than how he can remain with the most stars.
Even just with Favors and a #5 (say Gordon), Cleveland could argue that it's building a smartly designed team that (with Lebron) is both veteran enough to be an immediate contender and young enough to improve rapidly as Lebron himself ages. The roles would make sense (Lebron, Kyrie, Waiters, Favors, Gordon as scoring options 1-5). Favors and Gordon would be great at their roles even early in their careers. Front court defense would be superb. Pick and role possibilities would be incredible if Blatt got Waiters to buy in.
I don't know if this is the best team-building option Lebron could find open to him. But I think it's one that the Cavaliers should be able to sell him as very attractive. I think it's potentially more attractive than selling him a weak-defending Jabari who plays the same position and needs the ball in his hands or a Wiggins who may be great in a few years but does not offer nearly the same role-playing promise as Gordon+Favors do in the meantime.