What about a sign and trade of Russell from the Lakers? Harden would fit the Lakers timeline and while Russell isn't great, he is at least a decent 3rd or 4th option for Philly. They'd have to commit to at least 2 years though (with a 3rd year option) which would also hard cap them, so maybe they don't want to do that, but I do think that would be an interesting trade for both teams.
If VanVleet does leave Toronto, I could see them potentially being interested as they have too much talent to tank, so upgrading the PG spot to Harden might push them into a solid playoff team. Boucher, Young, and Porter works dollar wise.
Pelicans would be interesting as well given they are a mess. Harden would actually provide something they need i.e. a great distributor that actually generally is healthy.