I'm with you on the starting Grant Williams part - I feel it's going to be very hard to see consistent success with Smart, Horford and Timelord all on the court at the same time as pretty much non threats from outside.
Grant is certainly no stud, but if there's one thing he's done very well (and consistently) this year it's make open threes. He's shooting 43% from three for the season, and having him out there to stretch the floor IMHO could really help to open the lane up a little more for Tatum and Brown.
My reason for not wanting to ditch Schroeder and Richardson are similar. Out higher percentage three point shooters this year have been:
1. Grant Williams (43%)
2. Josh Richardson (40%)
3. Payton Pritchard (37%)
4. Romeo Langford (35.5%)
= 5. Jaylen Brown (35%)
= 5. Dennis Schroeder (35%)
This team has shot 34% from three for the season, which is 22nd overall. I think that has really hurt the team' success in a big way, and I can only imagine how much worse that would get if we send off two of our top six outside shooters. Unless we manage to bring back an excellent shooter or two in return to fill the void I don't like it.