It's a system of "Accepting/Producing" subtypes, so I have the P functions all together as a lump sum of sorts; same with J functions. Fe-IEI would mean there's more of a focus on Judging functions, Ni-IEI would mean there's more of a focus on Perceiving functions, and though "I" and "E" would be implied in the subtypes, I see no reason at all for that to mean anything, let alone for that to hold hard and fast.
Everything would spread out like branches and limbs from a tree, more or less
I do notice you place far, far more importance on the concept of temperament than I do...