wanted to deny your last statement. But I'm not sure any more ...
First: Might reach a twilight zone of my English now: I'm used to rims that offer a small recess (the English translation of our German word 'Punzung' says 'punch', but I'm not sure if this is correct this time) to the nipples of the spokes. The word 'punch' is that twilight point!
I'm rather sure, that I never saw anything else on a rim for a motorbike. So the number of spokes that could be used on the rim is not 'dictated' by the number of holes in the hub but limited by the number of punch(e)s on the rim. Or the other way round. Even the holes in the punch(e)s must have the correct angle to line up hub, spoke and rim.
I searched about 2 dozens of your pics to get a clear and big view to your rims. Didn't get one as good as I wanted. Tried to enlarge some of them, but with no clear result. It really looks like your rims do not have any punch(e)s and thus would enable you to marry any hub to any rim. Reminds me of the wheels of my old mountain-bike that are built that way, too. But leaves me a bit concerned about life-time-strenght of the wheel ...
Hopefully greetings, Bambi
'Find me kindness, find me beauty, find me truth ...'
(Dreamtheater, Learning to live)