You get a starting lineup with rondo, gay, smith and, cousins. And you are worried about backup needs and wiggle room. That lineup is what teams wiggle room is shooting for. You don't forgo the chance at two star level players at pg and PF when those positions are needs themselves because of backups.
Collison, brooks, Landry, Evans, acy. Are solid backups. You don't do this trade and two of those are starting and you have JT and Williams as backup SF and C. You do it and starting lineup improves tremendously as does backup pg and backup PF. So you replace JT with Moreland,Evans,acy as backup C. You acy,smith or sign FA for SF backup