With the Kings at 13-18 and Fox’s future uncertain, I’m not sure how much they would consider trading him, but the Spurs are monitoring his situation. I think this is a fair return.
4 unprotected picks and Stephon Castle for an All nba caliber point guard sounds like a pretty good deal, and the Spurs would be a contender soon in a couple seasons. Fox and Wemby would be an insanely good duo.
Kings get Castle who they could build around and has looked good so far. They also get picks and Keldon who could be flipped in the future. I think this is a fairly good trade.