I think they would have been a top 4 without Tatum if they brought last year's group back. Then Tatum's return being the impetus to make them a true title contender or not - depending on what level he is able to perform at this year post injury.
The East is weak at the top of the conference. This would have been a formidable team without Tatum. Their experience / know how / chemistry. They would have been a talented group.
A bit like the Raptors after Kawhi left. They went 53 wins 19 losses. Or the Bulls after MJ left in 1993. The Bulls went 55-27.
I would expect this Celtics team if brought back to be a 48-52 win team without Tatum. That type of range. I believe that will be enough to be a top 4 team in the East given the weakness at the top of the East this year. Then Tatum's return being the piece they need to change them from a good regular season team to a true title contender.
This.
Team may not have kept Kornet but with Queta's improved play this year, I think that becomes a non-factor. team wouldn't have Simons' offense but we'd have Jrue to play steady PG which would hopefully help White play like his normal self and push PP back to the bench where he'd hopefully be playing at his normal level. C's keep KP, Al and Jrue and this team is challenging for the best record in the East this year.
Not sure if Brad still signs Minott and Garza but if he does, C's bench is very solid. With Tatum out, not sure how much time Baylor, Hugo and Walsh are getting but we'd be in less of a position of having to rely on any of them to make a major contribution this year.