I already have a framework in mind for the infantry unit idea, it would only need about 10 people initially to work - I expect a 50% drop-out rate over the first few of rounds of posting, giving 5 or 6 survivors of the initial scene... By having that scene actually be part of a battle, the drop-outs are simply killed or wounded by enemy fire. This would be made plane in the recruitment thread, by the way, so that people would be aware that if they drop out their characters will at the very least end up wounded, if not dead. "If you don't want this to happen to your character, don't drop out!"
If someone drops out and then wants back in, they can have the character recover, and return to the unit. Medical science being what it is, I would expect that most non-fatal injuries would be treatable.
As I said, I love the idea of a ship crew, five or ten people, and I would love it to work, but... I don't mean to be negative here, but I have run a couple of games of that sort, been in about a dozen. Always, the issue is that people loose interest and drop out, usually mid-scene, and usually people with key characters - the first officer, the pilot... And without those key characters, the game stops.
The beauty of my idea is that no matter who drops out the game continues, because infantry units are designed with a specific "command structure" so that if the commanding officer is killed or wounded the next most senior officer or NCO takes command.
Of course a military ship is designed that way too, but for a ship with a crew of 10 to suffer 50% casualties would be pretty disastrous anyway, there would have to be some pretty drastic damage, which would probably leave the vessel unusable...
Anyway, if there is sufficient interest, I will happily GM the "soldier-girls" game. My idea is that I would control the commanding officer, all senior officers and most of the enemy troops. I would need a Co-GM to control the senior NCO and most friendly NPCs. (There would be occasional trade-offs with friendly and enemy forces).
The player characters would most likely be privates/marines/rifles/troopers - depending on nomenclature, which isn't important. There may be opportunities for some of the platoon to get field promotions, if they survive.