this can not be done because of the cavs being over the second apron, but they could first dump a minimum contract player, then do this trade.
Very risky trade of course, but they basically change jarret allen for lively which makes them younger and taller, then AD for Garland may seem bad, but if you actually see the games, the Cavs are elite because they are redundant in the sense that despite the duplicate benefits, its also duplicate weaknesses.
Offensively Mitch, Mobley and Hunter along with shooters already is elite, and they obviously are better with garland's playmaking and Allen's rebounding.
But defensively they need to "hide" garland, while also avoiding that allen gets exposed on the perimeter.
Trading Allen for AD means Mobley gets fully unlocked to play Center and AD gets to play PF. On top of that you get backup with Lively to rest AD enough.
Trading Garland will make the team bigger as now their smallest player will be Mitchell, so defensively is an improvement, while offensively we have seen him be capable of elevating when it matters most, plus is not like right now when garland is hurt and is an absence, he will now have AD to put pressure on the paint, opening perimeter for him. Kind of what Jimmy has done for Steph in Golden State. AD in worst case scenario is constantly hurt, but so has Garland been, and AD will mentor Mobley to fully unlock him