the most tension is the Right rear spokes a scosh heaver on that side of the wheel bit stronger on the hook, given thats where some spokes go
I've got a 25 year old wheel with 36 straight gage , 3 X , 15's. so could do fine
I admit its sporty, E2 [non CD version of same rim]
I don't haul cargo on that bike. ... You know, Your MMV .
of course if you want to try to build rather different wheels , as 36 count.
36 also lets there be groups of 3 spokes. ...How about Crows foot..
group= 1 radial spoke and 2x2 cross. perhaps..
what the heck ..