Pg...this sounds like the kind of stuff us long timers use to go BAMA & HOYA on when it came to who should replace DRob. So many people wanted Michael Olowokandi- I hated that option so much, I called him SUCKMYWOKANDI. All those other players you talk about, are untouchable with how fiscally responsible they are.
Plus, Pop isn't so overly reliant on 4 down anymore so why are are we talking about Tiago's post up ability. He has decent ability, but it's the other things, it's the shots he doesn't take where a perfectly placed pass is more effective. Some of those other peeps you talk about on your list are BLACK HOLE BALL STOPPERS.
This Spurs team isn't heavily reliant on post ups and when Tim is gone, then perhaps what you say will pose an issue, or, knowing the Spurs, they'll have Chip find a way to work on his lofty release.