Maybe. It depends on other roster moves. They'd need someone to replace Al, but they are going to need that anyway.
I don't know how I feel about Beal. But adding him to Tatum and JB is a lot different than trading JB for him. The team would also be banking on TL's health.
In an ideal world, I think the C's #1 target should be Mo Bamba but heh. Or Jalen Smith. I don't know how either would work.
edit: I agree if the only move is Beal for Smart and Horford, the team is worse. But I also think they'd be getting the best player in the deal and there would be ring chasers lining up to sign for Boston.
Yeah, a sign and trade for Beal (which that post posited) is a terirble trade for these reasons:
1. The team is worse
2. The defensive identity is gone
3. The hard cap comes in so they can add nothing and end up shallower than before
4. Everyone plays up a position which makes 3 of those guys worse (Tatum, Brown, TL)
5. You set up Jaylen to lose touches, just as he's deciding if he wants to re-sign (he probably is fine playing the 1B or 2 to Tatum, he's not going to want to play the 3rd wheel to the St Louis duo)
6. You take up a huge amount of cap on your highest paid player likely being a not top 25 guy, entering his decline years.
Luckily word is Beal is taking him 1/4 billion to stay in DC and we can get players who fit our team structure better and help us win.