Sure

because that's how it works right? You just need to ask nicely and models, animations, maps, everything will appear, right?!
The reason why devs dont put it right from the start its because no one ask nicely so now that you did we can expect a new patch with not one, not two but five new factions.
But I'm being rude, surely you understand that making anything takes time and effort, video-games or mods are no exception.
So I can only expect that the "please read me" in the title means that you already started to make these factions, you already have plans, models, animations and maps to be tested but there's just a few details that need to be cleared and you forgot to add that part to your post?!
But no worries this community is quite helpful, any question you have they'll answer but they wont do the job for you.
PS: You can always read this,
[Faction] Polish Forces - development update #1 , and like that highlight says they're working since 2007, that's... 7 years to make one faction, just imagine 5.