Lol... It'd be far more than that. I'd say we could have a main character with other characters if you could handle it. We'd have a ton of NPCs who may or may not be in the RP on the long term, who may or may not be important.

Inept rookies probably won't exist. There'd really be the best of the best in Xcom, but inexperienced against aliens predictably...

Furthermore, it would be some time before this starts as I prefer to get the system right before I begin. Also, it will likely be an advance RP, though I don't really like categorising things, so the end result might have traits of both casual and advance RPs.