I think they need to move on from Walker.
If the Clippers flame out, I think i'd try something like this
Walker, Thompson for Zubac, Beverley, Morris as the basic framework (hard to tell exactly where the numbers will fall on if more needs to come to Boston)
Gives Boston a young big man, who hopefully can pair with Williams, but either way gives a nice 1/2 combo at center.
Then I'd try to trade Smart for a younger better offensive player. Someone like Bogdanovic or Bertans would be a nice target.
So if you do that you have roughly (with a spot for the 1st rounder and a F.A.)
PG - Beverley, Pritchard, Edwards
SG - Brown, Fournier, Langford
SF - Tatum, Nesmith
PF - Bertans, Morris
C - R. Williams, Zubac, Wagner
I think that team while not a dramatic change, has a lot more depth, some younger better fitting pieces, etc. And Boston would still have the draft picks and salary needed to go after someone like Beal should he become available.
I like this one a lot. I'd then flip Pat Bev along with Grant for Rubio who would help with ball movement.
Then trade Smart and Edwards to ATL for Bogdanovic and draft considerations
Re-sign Fournier, Kornet, Ojeleye.
Draft Davion Mitchell and Isaiah Livers
R. Rubio - P. Pritchard - D. Mitchell
E. Fournier - B. Bogdanovic - A. Nesmith
J. Brown - R. Langford - S. Ojeleye
J. Tatum - M. Morris - I. Livers
R. Williams - I. Zubac - L. Kornet