Starters : PG - Tony Parker SG - ????? SF - ????? PF - ????? C - Tim Duncan. Bench : Antonio Daniels Malik Rose Bruce Bowen Thats the team the Spurs have now. Fill in those question marks. Thats what they need. Ginobili might be the answer, I haven't seen him, so I have no opinion. But for arguments sake, lets give him the benifit of the doubt, and say he's an above average NBA starter. But that leaves another swingman, and another starting big man to fill in. Fill those in, thats what they need. Bench is good, still need three more legitimate starters though.
See Tracy McGrady and Grant Hill, both of whom were able to get that very same amount of money through a simple sign and trade. Toronto got a 1st rounder and Detroit got Wallace and Atkins, who were going to Detroit anyway. As for Orlando being a sorry team - extending on that using a simple analogy would put teams like Chicago, Houston, and Atlanta as NBDL caliber. With Duncan, Orlando would immediately be a title contender; with a healthy Hill, they would likely make waves in the playoffs. If Duncan did choose to leave, I would imagine it'd be the same - unless, of course, he wanted to spite the Spurs or the Spurs were fed up with him, neither of which I see. The difference isn't $30 million, anyway - 2 years ago, it was 6yr at $70m vs 7yr at $93m - a difference of 1 year and $23m. It's likely the contract would be extended at about $15m a season, making the difference only $8 million.
I think that at least one of the guys you listed as bench players could start...But, you're right, they would be better with those three off the bench, and three solid starters in their places.