Hi Don;
Proper glue joints are always at least as strong as the wood itself, so it doesn't really matter how many/how thin the extra strips are. I would only use thickened epoxy for the glue, however, since you're not glassing the entire paddle and need a really waterproof joint. For my need-to-be-waterproof glue joints I use epoxy thickened with milled glass fibers, that stuff is strong! 
Also, as has been pointed out many times before, don't exert too much clamping pressure, you don't want to squeeze all the epoxy out - Here, a visible glue line is not a bad thing . . .
Best Regards, Spidey
