I just checked Volume 31 in my closet. You're right, Viz translates #16 into saying Kamiccolo rivals #17 & #18 in power. I'll edit it into the following considering:
Piccolo: 800
#17: 750
#18: 700
I'm considering making it to where Piccolo is the same strength he was against #17 in the Boo Saga and making it to where Toriyama forgot he ever went into the ROSAT. There's just no other way for this to work. Thoughts?