There will be 16 Minor Factions, and we have 5 primary resources (Food Industry Dust Science and Influence), so there will be some overlap. Conversely, when a faction has the same base resource bonus, there are chances the faction has a similar ideology.

@BlackBird1696: Minor Factions will unlock various hull types depending on the faction itself. These hulls will belong to one of four great families, visually (because we can't afford to have 16 times X hulls per faction, production-wise).

UndeadPuppy wrote:

And they will probably get different homeworlds and ships as well. 

God I hope that they get different ships. If we can get access to minor faction ship designs after assimilation and those designs include cruisers I will worship this game for life.

Based on what was said in the Gamescom footage, each minor faction gives a bonus but also has a specific FIDS they are best at working.