Though you are bound to screw up somewhere.... Man those files amount to Megs of code for a reason.

Anyhow: this is not quite as unrealistic as you may well think. MIC's are an abstract representation of a way to recruit troops. Encomprising all the industry & logistics & management a faction may have needed to; represent through one "building". It's more like building up the social & economical model required to recruit troops your own factional way.

Calling upon regional troops is therefore a cultural defined thing to do (Romans would organize them as socii and/or auxilia; Western greek factions would use the polis-system; and Eastern Greek factions have yet another (albeit partially derived form Western Greek examples) way to do so.)

Factional troops however represent the troops you would recruit for your main military: garrison & campaigning armies. Those explicitly rely on a faction-wide "homogenous" system of acquiring everything needed to raise an army and support it with provisions etc. As far as money is concerned this is also represented through the cost of units; but as far as the underlying management goes this is what the MIC is for. The social & economic structure is what is represented through Governments; which determines the level of MIC (hence the level of central management) can be imposed on the region.

The Governments, in turn, are bound to the level of cultural; ethnic & social similarity to your own society prior to your conquest. Within the limitations of the game engine (it's all black or white; rather than a grayscale) this is a very accurate way of portraying the characteristics of the relationship between the "ruling-center/class" & the masses below, fine-tuned for each faction.