Ok not a question about size but one about usage or does it not mater?
for example there is the 3 by 50mm (ish) and you can get adaptors from the 3 hole to a larger 6 hole. and you can go from that to an 8 hole if you really wanted.
so my question is would the three hole be OK on a Mini (mine)
as i have a weld on QR that is 3 bolt! mmmmmmmm
oh would be looking at getting a new wheel to suit.