If you could get Mitchell without Tatum or Brown, I think you'd have to do it, though the cost would be immense. If Utah would do something like this, I think you have to do it.
Smart, Rob, Grant, Pritchard, 25 1st, 27 1st, 29 1st
for
Mitchell
I just don't know if that is enough because there is no clear star going back to Utah and that seems like the type of trade that needs a potential star going to Utah.
Post Trade even more roster holes
Starters - Brogdon, Mitchell, Brown, Tatum, Horford
Rotation - White, Gallo
But if you did the trade in the next few days you could then use the TPE either with Utah (Clarkson?) or other teams
Ainge is blowing Utah up. He won't be looking for talent and contracts. He will be looking for high first round picks, as little long term salary as possible, salary dumping, if possible, and high end talent on rookie contracts.
Ainge obviously likes Smart and Rob, but they both do have value. He could likely move them and collect at least a couple more 1st rounders if he wanted, but I also think he might keep them as they aren't going to move the needle a bunch on the wins and losses, but could create a nice lockerroom environment for a young team. Grant and PP are both still on rookie deals. Not star potential, but both look like solid rotational pieces and you need those kind of players on a team. 3 unprotected 1st's down the line.
If Boston needed to add teams to send Smart to, for assets immediately, I think that could happen. I mean would Cleveland want Smart and send Sexton to Utah. Sexton is basically Mitchell lite and Smart would be a great compliment to Garland, Mobley, and Allen. So something like that would make sense.
Trade 1 - Beasley to Boston into TPE for multiple 2nd round picks
Trade 2
Boston - Mitchell, Gay
Cleveland - Smart
Utah - Sexton, Rob, Grant, PP, 1st's (25, 27, 29)
Utah clears out a bunch of salary so they can acquire Sexton via sign and trade. They get a #1 young scorer locked up long term. A solid great value young center locked up for several years, a couple of rookie contract rotation pieces and 3 unprotected 1st rounders well in the future (so they may have more value). That seems like a good value for Mitchell, Beasely, and Gay.
Cleveland could really use a guy like Smart. They need some his nasty and I think he'd be a great compliment to not just Garland, but also Mobley and Allen. The Cavs would be a top tier team in the East next year if they stay healthy. They'd have excitement, and they don't appear to want Sexton back anyway, so getting Smart for him is a good value type move (also cheaper).
Boston gets a much better 3rd option (or a 2nd option pushing Brown down) and Brogdon then becomes the best 4th option in the sport. The top 3 players are all in their 20's and signed for multiple years. The team clearly needs some big man depth, but there are some vet minimum guys around and White may be expendable with that roster configuration to find the players needed.
Boston post trades and signing Dwight (or Whiteside or someone similar) to a vet minimum
Starters - Brogdon, Mitchell, Brown, Tatum, Horford
Main Rotation - Beasley, White, Gay, Gallo, Dwight
That seems like the best team in the sport, if healthy. No one could defend that starting unit and they have plus defenders at 4 of the 5 spots. And the overall talent is there with a top 10ish player at the top, 2 top 20ish players, and 2 top 40ish players. You have a good mix of scoring and defense on the bench.