Ginobili actually does better coming off the bench than starting, correct?
That's part of the reason why he doesn't start; not just because SA has a strong bench.
Somewhat my point, except the Lakers have the better bench, i.e. Farmar/Vujacic/Walton/Powell/COBY. Spurs? Decent ones like Stoudamire and Bonner, but they are getting much older. The chemistry might not hurt considering they have to get accustomed to having Gasol AND Bynum in the starting lineup anyway. Lamar's been the third option behind Gasol and Kobe last year, and is now their fourth option behind Gasol, Bynum, and Kobe for goodness sake.
Jackson can certainly find some logic by putting Ariza in at the 3. That way, they can match up with those teams that have young and tall 4 and 5 spots (ie Jazz with Okur/Booze, Hornets with Chandler/West, and Blazers, yes BLAZERS, with a threatening combo of Aldridge and Oden) and STILL have the speed, defense and athleticism in Ariza, a much better defensive player than Lamar AND a million times better than Luke Walton will ever be.
It's worth a shot. Who knows, Lamar might play better off the bench and pull the sixth man award away from Manu or Ben Gordon. Who knows?