Interestingly, from the deals discussed thus far, the Kings don't technically need a third team. Hill and Malachi make $21.5M overall, and by cap rules, the Cavs have to send out a bit over $17.1M to get those two. Shumpert and Frye make $17.7M, so Hill/Malachi for Shumpert/Frye/(whatever terrible draft pick we are settling for) works without a third team. (The same goes for Skal instead of Malachi.)
Thus, if we were content to dump Skal or Malachi for literally nothing, there's no need for a third team. For us, the need for a third team would seem (at least under the framework of the deal as rumored so far) to be reserved for a situation where we *didn't* want to give up Skal/Mal for nothing. We could send one of those players to a team that could absorb them in exchange for a pick, then have a roster spot to fit in a Hill for Shumpert/Frye/pick 2-for-1 deal. But in that case, the third team would be giving us *positive value* for Skal/Mal, and not as rumored be fleecing us in order to take them - because we don't need that.
However, it's possible that the Cavs need a third team, because they are refusing to take back 2-for-2 in the trade. Why not? Well, perhaps the Cavs want an open roster spot to do something like trade the BRK pick for DeAndre Jordan. That would leave us in a tough spot, however, because if we're not getting a piece of the BRK pick, and we're not getting the CLE 2018 pick (because they can't trade both), then we're getting absolutely nothing for George Hill.
It doesn't make a lot of sense from our side, as reported. I don't know what to say other than that.