It wouldn't be a starting five, but Simmons at the point with Smart, Bradley, Crowder, and Olynyk would be a really neat and versatile small ball unit.
This is the unit I'd want to roll with, whether it's the starting unit or not. See what they can do.
Maybe put RJ or Rozier in there at Bradley's spot and see if they can do anything.
Whatever team gets Simmons should look to install him at the 4 from day 1, alongside a SF who can shoot a bit and also switch onto bigger forwards, and otherwise surround him with quick, skilled guys who can run and space the floor.
I think the focus of the team if they get Simmons should be to identify the players on the team who are on a similar timeline as Simmons (i.e. they'll be in their prime around the same time), with a skillset that compliments his skillset, and move on from the rest. Try to have the best team you can possibly have right around the time Simmons is really coming into his own.
My worry would be that the team would try to bring Simmons along slowly and stick with mostly the same formula that has had them in the playoff mix this season and last, instead of focusing from day one on building the best team possible around Simmons's unique talents.