This is an important dilemma. Assuming Walker (most do, I'd look for trade offers), Brown and Tatum are staying then keeping both Smart and Hayward is probably financially unsustainable. Especially because the cap doesn't look to be increasing in the future as much as was previously projected.
There are rumours that Hayward wants to sign a 'Horford-type-of-deal', which would mean around 100/4. The question whether Hayward is worth such a contract is valid, but I think he is. Due to the salary structure of the team I'd probably wouldn't want to go higher than about 80-90 million.
But in the case the salary cap will basically stay flat in 2022 and 2023 the luxury tax will go through the roof. It will be extremely expensive if we'd resign Smart as well. We could be 25-35 million over the luxury tax cap and be paying a luxury tax of 60 to 100 million both years.
So this is a very difficult situation. On one hand I'd like to persuade Hayward to take a 85/4 descending type of deal, but on the other hand adjusted cap projections could force you to look to trade Smart or let him walk (unless you think Marcus would take a very teamfriendly 10-15 million a year and even then we could have a record breaking tax).
Kemba is a very good player and a good guy, but that contract is going to bite us in the ass. As someone has frequently argued here the signing of Walker implied the end of Hayward's tenure with the Celtics. Letting Hayward walk or sign-and-trade for a lower expiring contract would solve the tax problems though.
I'm not sure why the cap is such a worry here. We aren't going to be below the cap anytime soon. If the option between these players is to trade one of them, then we are getting salary back and we stay above the cap. Unless it is expiring - but Haywards is already expiring.
I agree that the more important financial concern is that keeping Hayward's (or equivalent traded-for) expiring at his current option-year level for this coming year leaves us over the tax line.
Hoping Hayward walks is the last thing we want, because while it would drop us below the tax line, we would lose his talent, and yet would still be over the cap. That would only open up the non-taxpayer MLE (compared to the taxpayer MLE instead)-- hardly worth it. We would have no way of replacing his talent.
The best option for Danny would be to re-sign Hayward on a new multi-year deal with a base-year-compensation in the low 20s. Give it two 8% raises followed by a decrease in the final year(s) to ease the tax number down the road. The dropping of the BYC by about 10M would get us under the tax line this year, which pushes off the repeater tax until 2024. That's a huge deal.
This would keep everybody of significance under contractual control and also have both Smart and Hayward on tradable contracts if needed down the road.
For Hayward, that would lower his money this coming year -- though not by as much as it looks because of the escrow deal would eat into his current 34M significantly -- but give him long-term security.