Still not convinced this is the correct path, as far as not preserving a max slot/player to put next to Tatum and JB, but I feel a lot better about it now than I did before.
Maybe Ainge's mentality was dated, and the league as shifted in a way that having a few superstars and multiple mid range contracts/talents around those two players has become a recipe for success?
There is no one size fits all for building a contender.
I've never understood the way people here cling to this "we need a 3rd big star to compete".
Boston kinda started the modern "big 3" thing in 2008 and they got a title for it...but they didn't have just any big 3. They had the best shooter in the NBA, one of the best (and most clutch) scorers in the NBA, and a defensive player of the year - and any one of those guys was capable of scoring 30 on any given night, and were coming to Boston after being the #1 options on their own teams. Not only that, but it also happened at the perfect time - when all three guys had achieved their individual accolades, and were at a point in their careers where all they genuinely cared about was winning a championship...and they were willing to do whatever it took.
Boston's big 3 collaboration was kinda like taking a prime Giannis, a prime Steph Curry and prime Jimmy Butler and throwing them on the same team at a point when all either one of them cares about is winning a title.
Likewise Lebron, Wade and Bosh / Love, or Steph, Klay and KD. These aren't just your regular "big 3" rosters. There are "two MVP candidates and a perennial all-star" type scenarios. And even then Boston only got one ring, Lebron failed a number of times, and the Warriors got knocked off once too.
A big 3 arrangement like this is I think very tough to pull off. First you need to try and get 3 guys of THAT talent level together in the first place. Then you need to get them at a point in time when they are willing to sacrifice their own personal glory for the good of the team. Then you need to hope and pray and one or two fo them dont have major injury problems (e.g. Brooklyn, Lakers) - because when you depend THAT heavily on three guys, loose two and it's all over.
I honestly believe that teams would be much more likely to have a good shot if they have two big stars, and then divide that 3rd potential max salary slot over 2 or 3 really good role players to build a team that's well rounded and deep. That way even if one of your star guys gets hurt, there's a greater chance that the rest of the team collectively can hold help down the fort.