Is Brad the wrong coach for this team?
Let me start by saying Brad Stevens is an excellent coach - no doubt. However, his reputation has been earned from taking young, inexperienced, and underestimated rosters and getting them to overachieve and play above their expectations. Perhaps once he has a roster that is expected to achieve great things, his message or style is not as effective.
Doc Rivers, for example, was the opposite, he was really successful with a stacked roster. He knew how to massage the egos of his superstars (the Big 3) and lead them to a chamionship. His record of overachieving with a lesser roster was not so great.
Is Brad's problem that he has not clearly set out the roles of the various players on this team? Is he "afraid" to ask certain players to sacrifice and accept lesser roles? Are players not listening to his messaging and accepting their roles?
It seems that the team lacks a cohesiveness. And that is on Brad. The players need to know their roles and accept them. If a player cannot sacrifice for the betterment of the team then it might be time to look to trade him for solid role players.
I think the issues sit with Tatum, Brown and Rozier. They are trying to find their place on this roster. If this isnt settled in the next few games it has the possibility of getting ugly.
Looking back to the Big 3, Pierce, KG and Ray Allen were the clear scoring options in that order. Perkins was the muscle and defense and Rondo was the facilitator. KG was the heart and soul.
The bench had Posey and others that filled roles as needed.
This teams current starting 5 lacks a Perkins/KG presence, and a facilitator.
This current roster, lacks experienced role players who know and accept their role other than Thies, Morris and Smart and they only have one player with heart (Smart).
Definite Starters (assuming health)
Kyrie - should be scoring option 1
Hayward - should be scoring option 2
Horford - should be scoring option 3
Potential starter
Baynes - does not need the ball, adds toughness
Brown - can be scoring option 4, adds defense and main focus if starting should be defense.
Tatum - this year has become a chucker, can be socring option 4, but would be better as lead bench scorer. Defense is lacking.
Role Players
Morris - accepted role and is thriving
Smart - accepts role and doing Smart things
Thies - 2nd year, but plays his role well
Rozier - finding his way - rumors that he wants out
Ojeleye - still developing
Yabusele - still developing
What I would do.
Start Baynes in place of Tatum - starting 5 - Irving, Brown, Hayward, Horford, Baynes
BWA - Smart, Rozier, Tatum, Morris, Theis
Defense Role - Ojeleye
Emergency - Yabusele, Williams, Wanamker