Brown for Simmons was the type of thing floating around last year, but Simmons doesn't have that value right now.
I tried to come up with a trade for Simmons that I think actually makes sense for all teams involved, and this is what I came up with
BOS - Simmons, Looney, Wade
GS - Horford
CLE - Wiggins, Langford, Pritchard, Milton
PHI - Love, Sexton, G. Williams, BOS 22 1st, BOS 24 1st
So Boston post-trade
Starters - Smart, Brown, Tatum, Simmons, R. Williams
Main Bench - Schroder, Richardson, Nesmith, Hernangomez, Looney/Kanter
Deep Bench - Parker, Fernando, Wade
Assuming Philly comes down on their value, then Cleveland seems like the team that may not do this as they might rather just try for Simmons themselves, but they don't give up any 1st's in this, which I think is key for them and I do think Wiggins would be a nice fit for them. GS drops a ton of a salary and I do think Horford would be great for them as they do lack someone like him i.e. a center that can defend and pass and shoot.