Uh, hang on. If you're a warboss with a klaw all your attacks will be S10. If you're a nob then they'll be double a nob's strenth, which does not equal S10.
Anyway, no there's no benefit to taking 2. You can only use the effects of one CCW at a time, so an extra klaw would just serve as an expensive 2nd CCW, to give you +1A, so you're much better off taking a PK+Choppa to get a better effect, as you get +1A for 2 CCWs, and a bit of versatility to boot.