ATL isn't in free fall without Horford, but there is too much payoff to pretend to be competitive this year only to end up with a 12th pick.
ATL trades: Paul Millsap
DET trades: Greg Monroe, Josh Harrelson, Chauncey Billups
For ATL, they get a long-term piece moving forward to put next to Horford who toes the balance between potential and realized talent in Monroe. They can decline Billups, and waive Harrelson, or not.
DET gets a stretch 4 who complements Drummond and allows Smith to guard 3's but space the interior more (Millsap is shooting 40% from 3 this year).
Millsap has improved his outside game, but I still think they have to trade Monroe for a true SG or even SF (Smith has to play 4, doesn't he?)
Even if Utah already has Favors, someone like Hayward would be a nice target for Detroit.
Or, let's say they are willing to take a chance on Eric Gordon's long-term deal. Monroe for Gordon and a first. New Orleans plays Tyreke Evans full-time at SG and figures out how to balance Anderson, Davis, and Monroe later.
Or maybe they call the Cavs and say ask for Waiters and Thompson + spare parts for Monroe.
Finally, I don't think Toronto is interested in dealing DeRozan and they have Amir Johnson but I could see Detroit asking about him.
I think what we can take from this is that there really is a dearth of good, true SGs available around the league.