i think this is one of those things that is personal preference

but that said, i've made nappies with 2rows of 6, and 2 rows of eight ..... i get a better fit on b with the two rows of eight.
but thats just us

in terms of where to put the snaps on the tummy, bring the wings to the front, estimate where the snaps will be on that, then just put the ones on the tummy where you're happy with the wings sitting IYKWIM
Working Mama of miss7yo and mr5yo.