Just throwing this out here for fun since it involves Horford and Conley (and since I consider Horford a full-time C these days, I can't really talk myself into taking him in as a Gobert backup/questionable PF). It's another trade idea that will (and should) never happen, though it does perhaps seem to solve several issues that are out there. I tweaked an idea on the internet that wasn't legal until it worked, it and seems to have some potential positives for each team.
In case there are problems with the image:
Utah out: Gobert, Conley, Bogey, Davis
Utah in: Hayward, Horford, B. Simmons, Theis
Philly out: Horford, Simmons, Mike Scott, Zhaire Smith
Philly in: Conley, Bogey, Robert Williams (and would probably need some draft considerations)
Boston out: Hayward, R. Williams, Theis
Boston in: Gobert, Ed Davis, Zhaire Smith, Mike Scott (the last 3 for salary purposes to make the trade legal, though Scott is at least mildly useful)
Advantages for Utah:
Off of Conley contract; let someone else take the Gobert extension risk; lose the best player, but get 2nd & 3rd best players back; all four are useful pieces (each decent to very good defenders if utilized properly); 8 man rotation would be: DM, Hayward, Simmons, Ingles, Horford, O'Neale, Theis, Clarkson (hopefully), before getting to Niang, Bradley, Morgan, Oni, etc.; (of course we'd also have the all-bitterness/jealousy team by adding Hayward and Simmons)
Advantages for Philly:
Fixes their books; allow for a path to build smartly around Embiid; seems to give a starting 5 that makes pretty good sense together: Embiid, Tobias, Bogey, Richardson, Conley
Advantages for Boston:
Gets best player in deal; eliminates Hayward's positional redundancy in the process; saves a couple million (and I think should be able to accommodate Gobert raise); Likely starting 5 seems great: Gobert, Tatum, Brown, Smart, Kemba
Generally I think the trade is interesting because it allows all three teams to stay below the tax this coming year (and I think it offers a path for all to stay there in the future, if maybe a little trickier); it also allows for a better fit for the three players who were being underutilized because of the original team's makeup: Hayward, Horford, Conley (not sure if the troubles maximizing Simmons has been totally solved, but maybe it's also better?)
I'll leave the disadvantages (many of which I'm sure I haven't thought of yet) to anyone who wants to take a crack at them.