That's your opinion of Neal's relative value, and you're very much en led to it. You should go over to the Think Tank for more-directed discussion on trade ideas. I'll say this here, though: There is no reason why Neal can't be a starting two-guard. There are systems like Phoenix' from years past and Orlando with Howard where Neal could start just fine. The reason he doesn't have that opportunity with the Spurs is that Danny Green fills the role better. Ideally, the Spurs' wings would be interchangeable, defending and shooting corner threes. Neal can't really play small-forward though, so that hurts his value in the starting line up. That's also the reason why Pop pushes for Neal to play the point off the bench.
Also, he can certainly be the centerpiece for teams like the Wolves. If they want to trade Williams, and (key phrase) if Pop thinks Williams could help the Spurs this year (and he'd have to, to commit the Spurs to that contract), then a Neal + filler for Williams deal is very possible. The better Neal plays, the more possible those deals become.