I don't see the upgrade others are claiming.
If it was just a case of losing Bradley and adding Hayward then sure, that would be a pretty significant upgrade. Still not a HUGE upgrade, but a very significant one.
But I don't believe you can look at our team this year vs last year as simply a case of Hayward vs Bradley. There have been a lot of changes which I think are going to hurt the team a LOT - possibly enough to offset any gain Hayward gives us over Bradley.
Firstly, this team's horrendous rebounding has given us major issues for some 2 years running now, and after the moves this offseason we have just gotten a LOT worse in that area. We have lost Bradley, Olynyk , Jerebko, Amir and Zeller. That's 5 of our top 6 rebounders gone. In return we've picked up Zizic (who may or may not be even capable of producing), Morris (who can't rebound to save his life), Hayward (a woefully mediocre rebounder for his size), Baynes (who probably wont get more than 20 MPG), and Theiss who looks to me like he will be utterly useless and probably won't contribute at all.
Secondly, chemistry is almost certainly count to suffer. We lost Bradley, the longest tenured guy on this roster. We've also lost Olynyk and Jerebko - nice solid backup guys who knew there role, played their role well, and never tried to do too much. We've instead added Hayward (who I think will fit in fine offensively) but we've also added Baynes (who has zero offensive ability and terrible hands), Morris (who wouldn't know what team offense is if it slapped him in the face) and a handful of guys who have never played an NBA game thus far an will take time to adjust. I am seriously concerned about how long it will take for our chemistry to start to gel, and I'm not sure if we will ever have the same offensive capability with this unit as we had earlier. Even Amir, for all his limitations, was an extremely efficient finisher around the basket, an intelligent passer, and a strong offensive rebounder who could also step out and hit the occasional three. He didn't do much, but he helped on the offensive end more than people may realize while he was on the court.
As for the Bradley/Hayward chance...Bradley was the perfect guy for the SG spot given he had the quickness and length to defend both guard spots, had the defensive toughness to cover for Isaiah's limitations, and had the consistent outside shooting to help create space for Isaiah. We've lost him now and I assume Hayward will replace him in the lineup at SG. That's fine on the offensive end, but I shudder to think of how bad Hayward is going to be defensively with Horford (instead of Gobert) there to back him up in the middle, and with Isaiah Thomas (instead of George Hill) alongside him at the PG spot. Hill can take care of his own man defensively, so before Hayward only had to worry about his own man. He didn't even have to worry about that much because when his man got by him, he had Gobert covering his back. this year he will need to cover his man AND help on IT's man - and there will be no 7'1" shotblocker in the middle to cover up for his mistakes. So based on sheer "sum of parts" Hayward is definitely a better individual talent. But Bradley's overall contributions as a three way player (offense, defense, rebounding) might eclipse Hayward's contributions as what is pretty much a one dimensional play who isn't very good at anything other than scoring.
Based on the significant drop off that I'm expect on both offense (due to chemistry) and defense (due to both chemistry and sheer defensive talent) I'm going to go out on a limp and say it's entirely possible that Boston, as a team, may well regress this year.
But I do believe that 2 years from now (once our young guys have some experience and start breaking out) we could become very, very good.
To me this year's moves were a very clear case of sacrificing one year in order to make us stronger in the future. I don't love that idea because I feel like we are legit one or two pieces away from competing with Golden State, and I would have liked to strike now while the opportunity is there...
But I get the move. Horford and IT don't have that much prime left in them, so if we went all in right now I'd say we probably only have window or 2-3 years. I can see why Danny would prefer to sacrifice some success in those 2 years for a good decade of success.
But at the same time I feel disappointed because it feels like we are wasting Horford and IT's best years on the hope that Brown and Tatum will become future superstars and help carry this team, and I feel that's a bit risk.