As far as I understand, cotters come in different sizes, 9.5mm is the usual English size, and French cotters come in 9mm. So on the main, a French crank is drilled to take French cotters, and an English crank takes English cotters. Is this the case?

My question is, are the spindles are all the same, English, French, Italian? Can I take a french crank with a french cotter, and mount it on an English spindle?

I see in this thread some very handsome cranks, like that 5 pin Durax. As far as I know, Durax is a French crank supposedly taking French cotters, can I mount it on say my Raleigh?