I'll list it one by one why I think this makes sense for every team,

The 76ers have addressed many of their needs in the offseason by adding in pieces like Paul George and Andre Drummound, however Darel Morey has recognized that the 76ers must improve on rebounding and defense, and not to mention the 76ers do lack a playmaking. Nicholas Batum will be missed by the 76ers, he made smart playmaking decisions and winning plays, being loved and given rotation minutes by nurse. He was going back and fourth on Philly and LA but most likely went to LA because of salary. When the 76ers decide to go ALL in they will want Batum back, and the clippers most likely will be a dumpster fire and looking to add young assets and picks, and B) The clippers added a stack load of depth in the offseason, leaving me to believe Batum won't get many rotation minutes, perhaps leading to the Clips being willing to give him up for, a young asset, a pick, and a guard who may or may not crack the rotation more as a catch and shooter. Jared Vanderbilt when healthy for game 6 against the Nuggets got 0 minutes, which may prove that they don't value him very highly, its also known that Rob Pelinka has been shopping Vanderbilt and values young assets, therefore a Mccain for Vanderbilt swap could make sense, because Mccain will crack the rotation as possibly the best backup PG, and future asset.( Not to mention he has high value being selected right outside the lottery) Jared Vanderbilt also happens to be a match made in heaven for Philly, being a great multi-positional defender with grit, a large power forward, and a fantastic rebounder on an affordable contract.