Yeah, I'm just trying to change his mind on this. My build will work mostly the same way.
Also, Complete Arcane errata even mentions that text trumps table and statblocks, so I'm even more inclined to say it is +15 CL on 10 levels. But if Prinny is set at +10 CL on 10 levels, that's okay.
EDIT: Forget it. There is an example within the very text of the ability that disallows it. I believe PrivatePrinny catched onto this before me. Can't believe no one ever mentioned this on the CharOp board back in the day... Probably because of the RAWxRAI debate always going on there, but the RAI is so clear here with even an example to go with that RAW is completly irrelevant.