So I had some more ideas regarding how the research and ranks could be handled in an XCom game.
Basically, we would have like 3-5 games running at a time. Could be more, could be less. The other numbers would have to be fudged a bit to make everything work at a good pace.
Now, this wouldn't be all games run by me, I would have to have several other people running games with their group, me running a game with my group, and maybe another game online just to square things up.
So what we do from there is everyone else reports back to me when their team does a mission. I take the information they give me, which will include what artifacts the team got, how many research points they earned, promotion recommendation (probably only for higher ranks), etc. Then they would apply their research points to a technology. When enough RP are given to a tech, that tech is unlocked and the tree expands. We can also communicate from team to team to buy, sell and trade gear from team to team (i.e. Team A needs more plasma rifles and Team B needs enough cash for a new ship).
That would handle equipment and research. Something similar would have to be done to manage manufacturing, however each team should do that separately, so they can actually race towards the final battle at [redacted].
I could write or help write missions similar to a plot point campaign (but with less plot points). This way each team could run missions. We could still have plot points, like the first mission, certain events (certain aliens showing up in the fight) and then the final mission(s). I think it would be fun to run a co-op campaign like this with several GMs running a game setting together to basically mimic all the different teams and giving a competitive edge to it for the teams.