It's coming up on 2 AM where I am, and I'm posting this nutty idea because it popped into my head and I can't get it out. I'm hoping if I post it I can get some sleep.
The idea is that you get the option of creating and customizing your own army. I'm thinking a few different details. You have to fill a few different niches (basic infantry, Anti-Armor infantry, specialists like commandos and hackers, Armor, Anti-Infantry Armor, etc.) with units of your own choice, and you can put an extra emphasis or extra units in a nich or two, but you don't have room to make an Army that completely dominates at everything.
Beyond that, you get to customize the gear that your units use, to different effect. For instance I could choose to equip my basic infantry with (among other choices), an AK (47, 74, whatever suits you), or some variant of the M16 (we'll say the M4 carbine for simplicities sake). If I choose to give my soldiers AKs, they take less time to train (as an AK requires less maintenance than an M16), and their guns have little to no chance of jamming (just a little effect that for a second cancels your unit firing). However, if I go for my M4, while my troops might take a little longer to train and do have a slight chance of having their shooting set back by about a second once in a while, they do have better accuracy (could mean less chance of missing, higher damage, higher critical rate, longer range, or any combination of the above).
You could also opt to give your units a limited selection of special abilities. If you want your guys to throw grenades as a special ability (whether they be lethal or non lethal you can choose what they're equiped with) to help clear out buildings, or perhaps camouflage, or even just training them to have a certain stat higher than others.
Vehicles would probably be handled a bit differently. You can pick what vehicles you get, but beyond that, what you see is what you get as far as their abilities and what they're armed with. I suppose there could be a weapons development mini-game, but that's a whole different issue. Probably more trouble than it's worth.
Finally, of course you have control over your units uniform. Possibly paint jobs for your vehicles as well, not to mention your own symbol/emblem/flag.
Now I'll address what I would guess would be the main obstacle to such an idea: Balance. How can EA, BioWare victory, or any developer hope to balance factions that they don't create. Simple answer: they can't. So scrap the idea, right? Well, there is one way around that. You make one PVP league for the set, developer-made factions, and another for custom factions. The custom league is where people can go against each-other's armies and compare what they have with each-other. However, this runs the risk of, after a certain period of time, seeing a lot of cookie-cutter armies out there when people figure out what the best combination is (and even if there is not such thing, if enough people believe that a combination is best, it will still have the same undesired effect). The answer to this is simple: the devs would have to continually add new weapons, vehicles, and abilities as DLC to keep everything fresh.
The idea is, in a world where Generals are taking over and dividing the world, you'd probably have a few warlords out there who would be making forces that don't always fit the same mold. That and the whole idea just seems like fun to me.
Any thoughts? Remember, I realize the idea is insane, but it's usually that kind of idea I have to get out of my system if I want any sleep.