Not even getting into whether those guys are good enough to even sort of replace Green right now (Mayo, seriously?). Thanks for the list. The issue is that every one of those guys outside of Hairston should make more than Danny next season. So if the Spurs traded Green to get Horford, it's not like those guys are going to be signable. You're going to see players getting Carrollesque contracts left and right this summer.
THJ isn't a three-and-D player. And he's not even playing Atlanta's injury-riddled wing rotation. I was going to say that maybe he could bring the offense that the Spurs also need to find. But I just looked up his stats, and he's a crazy-inefficient chucker. I'd rather roll with Anderson or Simmons over him.
Dinwiddie is under contract next season and is a PG (and a non-defen. Hill is only a UFA because the Pacers didn't pick up his option. That's not a definitive death sentence, but it's a pretty bad one, considering Indiana still needs legit wings to put next to George. In any event, these aren't guys you replace Green with. These are guys you bring on and hope you can eventually replace Green with. That's completely different. We all want the team to get a third defensive wing. Those would be guys to bring into camp to test that out, not guys for the starting lineup.
Maybe the Spurs could have swung a Lee side trade as part of a Horford main trade. That could have given the Spurs a body to put in Danny's spot at least. But outside of that scenario, it doesn't make sense. Horford is NOT a franchise player like guys are making him out to be. He's not a dude you sell the farm on.