Saws for boyz, klaws for meganobz.
If i get it right, meganobz can't take a kshoota+saw. It's either kshoota+klaw or double saws. In my mind a 35
ppm basic meganob is a steal even if he deals noticeably less damage. But that's still enough to wreck stuff.
Boy nobz on the other hand need every bit of antitank punch they can get. Or go cheap and take a big choppa