The rubber mounted "clamshell" "ragmount" (whatever ya wanna call the kit supplied POS lol) is designed for a conventional 36-spoke wheel as are most of the alternates. While you can of course make it work with more spokes and many have - it starts to get to be a nightmare.
It's far easier and in some ways better to go for a heavier gauge spoke than more of them, unless it's the fashion yer afterbut remember that even the heaviest gauge spoke won't do you a bit of good if it's laced into a cheesy walmart single-wall marshmallow-alloy rim lol
I haz "cheesy walmart single-wall marshmallow-alloy rims" myself, and between the abuse of the roads round here, the crazy bastid riding the bike, and prolly the stock sprocket mount - my rear rim in partic is never true.
*shrug* I'm sure they're good 'nuff so to speak, but they do not fill me with confidence lol I do know (unfortunately) they like to taco way too easily, while no rim is invulnerable - I think the rims I have on my bike are it's weakest link.
Potholes wait in ambush, jump out right in front of you when yer flanked by a cager and a gravel drop-off, I swear! I seen 'em!
sneaky o.o