It would also be better for Brown to come off the bench.
There's just not enough shots if he's with Kemba, Hayward, and Tatum.
Jaylen and Carsen would give the Celts bench a lot of firepower.
I'd love to see Tatum come off the bench. The C's could finally play with some teamwork in their starting five.
G - Kemba
G - Smart
F - Hayward
F - Jaylen
C - Kanter
Hayward and Kemba lead the show. Jaylen slots in comfortably as the third scorer. Tatum gets to come in off the bench, be selfish and jack up shots right and left.
Ever thought of starting Theis at PF against bigger teams like Philly? He's quick enough to play PF in "twin tower" lineups and can stretch the floor. As for smaller teams I think Semi/Grant Williams would be a good piece at PF, they both don't need the ball and can defend pretty well. I'd much prefer:
PG: Walker
SG: Brown
SF: Hayward
PF: Semi/G Williams/Theis
C: Kanter
I love Marcus Smart. I want him on the floor. I rated him as a top 10 SG last season. It leaves Boston with an undersized lineup but talent wise he is a huge improvement over Theis, Semi or G.Williams. It keeps a lot of individual talent on the floor while allowing Tatum or Hayward to become a 6th man.
I am a bit nervous about one of those guys at PF next to Kanter because that is two lower talented starters. Both bigs. Next to one another. If we had a better starting center, I'd be more optimistic about Theis, Semi or G.Williams as a low minute starting option (16-22mpg).
I like Theis as a PF next to a C against big lineups. That is useful option. Even if not as a starting unit, as a unit to be used later in the game while one of Hayward / Tatum / Jaylen is resting. Allow Boston to stay big, improve defense while offense takes a hit with one of those guys on the bench.
Semi's outside shooting holds him back as a starting option. For now, he is only useful for spot minutes here and there. I don't look at him for big lineups. More for an extra defender against strong combo forward types. Kawhi or Giannis. Rather than twin tower type configurations.
Grant Williams still has to prove himself as a defender. Hard to say about him. Is he better on bigger body players like Glen Davis was or is more comfortable on smaller quicker players (like Semi is). Need to see more reps from him. What I do like most about him is his passing ability. I worry about two non / limited passers at PF & C if Boston goes big. That is what Grant Williams can provides that separates him from the other bigs. He can maintain team ball movement and avoid Boston's offense becoming more isolation-based when / if they go big.