I take it that spread is for II 1? and everything would be 1 higher t II2?
I sort of agree with a few things sticking out a bit, an outpost generally speaking is brand new shiny population so would probably be better equipped than it would otherwise be, plus a -1 II will be pretty crippling to such a small income anyway, so from gameplay perspective it's pretty nasty.
Inversely, big pop's while I agree they're much less efficient, will tend to have the latest and greatest in industrial tech and processes.
another way to model that, while a bit more bookkeeping would be to spread any new II out from the capital, like ma jump rating out per turn or possibly per year to model having to recreate processes with the new facilities/processes when the II goes up.
All that aside keeping the one II empire wide is much simpler and more streamlined.