Smart, Semi, Green, BOS 1st, MIL 1st
for
Kuzma, Bradley, Cousins
I think I'd do that even believing Cousins won't come back this year. I just think Kuzma would be a real nice fit on the team and think Bradley could give you much of what Smart does (though not as well).
Post Trade
PG - Walker, Wanamaker, Edwards
Wings - Brown, Hayward, Bradley, Langford
Swings - Tatum, Kuzma, G. Williams
Bigs - Theis, Kanter, R. Williams, Poirier, Cousins?
Lakers get Smart who can be their do everything type player and is basically an improved version of Bradley and Rondo at this point. Add Semi as a defender down low. They also get a couple of late 1st's to replenish their young players or that they can use in trades.
Not sure either team does it, but I think it is a reasonable enough trade value wise for both teams.