The only way I can see this coming into play is an Anthony Davis trade where Hayward is the main salary going out. And to be clear I don't think Boston will move Hayward, but that would be the only way. So in that scenario the trade could be something like this
Cleveland - Hayward
Boston - Davis, Moore, Clarkson
New Orleans - Smith, Tatum, SAC, MEM, LAC, BOS 18 or BOS 19 (NO obviously cuts Smith as only a couple mill is guaranteed)
Let's say Boston brings back Morris and Baynes. So Post-Trade Boston ends up something like this
PG - Irving, Clarkson
SG - Smart, Moore
SF - Brown, Morris
PF - Davis, Theis, Yabu
C - Horford, Baynes, Williams
I'd say that would be a reasonable trade in this situation for all parties and the team Boston ends up with is a clear and easy title contender.
So if I'm deciphering this correctly, you are trading Hayward, Tatum, SAC, MEM(even if doesn't convey?), BOS18 or BOS19
for
Davis, Moore, Clarkson
Why do we want Moore and Clarkson? Not bad players, but hardly pieces we have to have.
That seems like overkill. You are moving way more salary than necessary to bring in Davis and bringing in pieces that are nice, but that we don't need.
I just don't get what 'drives' this sort of deal. NOP isn't going to be doing it for the joy of cutting Smith. Boston shouldn't be doing it for some compelling need to add Moore & Clarkson.
The only team that really wants to do this would be CLE. They dump Smith & Clarkson in exchange for Hayward!
But how does that become compelling for NOP or BOS?
NOP & BOS seems more likely to want a simple deal like Davis for Tatum + Smart + (Yabusele or other small contract) + picks. That's literally all that needs to go across to make the deal work.
Is the idea here that somehow Boston wants to get rid of Hayward's contract? I don't get that. If you are adding Davis you are going all-in. You want to have maximum talent for the next year in order to motivate him to sign long term.
And while I like what Smart brings to the team -- and really am impressed with how he improved his game this year -- the following starting lineup looks way more compelling to me than what you have above:
PG - Irving
SG - Brown
SF - Hayward
PF - Horford
C - Davis
(Granted Horford & Davis are sort of swappable at the 4-5).
I just don't see the 'albatross' of Hayward's contract to be a compelling reason to replace Hayward with Smart in that lineup.
Some of it is salary going forward based. Is Boston really going to maintain 4 max contracts? That is an awful lot of money to have tied up in 4 players. You tie that much money up, I think you lose valuable bench players like Baynes and Morris.
And obviously I think Hayward is better than Smart, but in many ways the team needs Smart's ability to defend both guard positions more than Hayward's playmaking and scoring ability. If you have Smart next to Irving, you can hide Irving a bit more defensively and save him up for offense and with adding an extra elite scorer like Davis you don't need someone like Hayward as much.
I also think there is absolutely an advantage in adding Clarkson and Moore to the bench. They add quality depth on what would be expiring contracts (so no long term commitment). At some point you need quality bench players (which also goes to Baynes and Morris), especially with Irving and Davis both having a propensity to miss a lot of games. Horford isn't exactly a spring chicken either.
As I said, I'd prefer to move Smart instead of Hayward as well, but I can absolutely see the reasons why moving Hayward makes more sense from a basketball, team construction, and financial standpoint moving forward.
As for New Orleans, the only salary they take in that scenario is Tatum, the draft picks (which they select), and Smith's buy out. They also get rid of Moore. That gives them a pretty clean cap sheet. In many ways, that actually makes more sense then taking on someone like Smart, who while has a reasonable contract isn't exactly the type of player a rebuilding team would actually need or probably want on the roster. Smart doesn't move the needle for them at all, while a cleaner cap actually might. They can then move Holiday and really commit to rebuilding and building up the right way.
Cleveland takes on a lot of salary. And while we've seen improvement from Hayward of late, he is still worth no where near his contract, and he could opt out in the summer of 2020 (or opt in and lock in a huge overvalued contract). I don't think he could really bring back all that much in trade given those things. Cleveland is paying a lot of money for what might not be a very good player. It also provides cap relief to the Pelicans and bench depth to the C's. They certainly could make out very well in the trade if Hayward regains his form, but if he isn't much better than he was this year, then it really isn't a good trade for the Cavs.