This team needs three things going into next season: (1) a dribble penetrator who can QB the offense and create for teammates; (2) a third big that can rim protect and shoot (i.e., the Horford understudy); and (3) a culture guy/leader/defensive tone setter.
I thought they solved #1 last offseason with Brogdon. He proved to be a fine scorer, but a pretty poor facilitator. I've also been disappointed with his decision making in high leverage situations. I thought he would be the guy to settle them down and make the play, but he's been as much of a turnover machine as everyone else.
I was disappointed they didn't try to solve #2 last offseason. They didn't build enough depth behind Rob and Al given age and health concerns. Gallo was a fine regular season signing, but he's not a playoff contributor. Grant playing his way into Joe's doghouse certainly didn't help. I'd love for them to find a way to get a guy like Wendell Carter Jr. here.
As for a tone setter and leader, Al and Marcus have both been this guy for them over the past few years. Ime also played this role last season from the bench. CJM clearly doesn't have the same impact on the locker room and defense that Ime had. And I hate to speak ill about Al or Marcus, two of my all time favorite Celtics, but the team's culture sucks and they've lost their defensive identity. To some extent, that's a reflection on them. They need a Draymond, PJ Tucker, Dru Holiday type that amps up the physicality and gets after the team to play better, harder, and smarter. I was hoping Grant would develop into that role, but he hasn't and Smart just isn't the same guy on defense as he was last year.
They are in a fortunate position in terms of their roster. Their floor with JT is the EC Semis. However, it seems their ceiling with this core is exceptionally talented but just not enough toughness to get over the hump and win it. I don't think they can retool the roster to bring in a facilitator, more toughness, and a Horford understudy by casting off Payton and Grant and signing vets. They need to shake up the roster. Moreover, the stench of quit that has followed them around this series needs to be torn out by any means necessary. Ultimately, this likely means everyone but Tatum is available and JB or Smart (and maybe both) are on the move.
Ime screwed the team over. They were comfortable with brain drain with Ime at the helm. Then as the season is about to start, Ime is out and CJM is in. The C's did not build a staff to support a rookie coach and then the top assistant leaves mid-season for a college job. CJM has been out coached out throughout the playoffs, but I can't see how they fire him. They put him in an impossible position. Plus, if they fire him, they are on to their 4th coach in 4 years. You never see that with a contender and the turnover kills the ability to build a certain culture. The whole reason why CBS became PBS was because he was ill equipped at building the culture on the bench and they needed Ime in there to "coach harder". Maybe CJM isn't that guy either, but I think he deserves a longer leash. I just hope they build a good, defensive minded staff around him, including a strong veteran assistant that can take the reigns from CJM if necessary.