One of the problems with running military games in an RPG is the chain of command: Realistically speaking, even on remote missions with a small team (i.e., ideal RPG fodder) there should still be one guy who’s actually in charge of the op. This can either be an NPC (which can either lead to railroading or, for the GM not interested in railroading, a really tricky balancing act between having the NPC commander do their job vs. letting the players take the initiative). Or it can be on of the PCs (which can remove the dilemma created by requiring the GM to issue literal orders to the PCs, but which can result in incredibly fragile gameplay that’s highly dependent on the player running the captain).
On my bucket list is running a Star Trek-like open table campaign where every player designs a captain and their bridge crew. When a player requests a session, that player would be running the captain and anyone else who shows up for the session would pick up the roles of their crew troupe-style (meaning that those roles would, over time, be played by a variety of people). This doesn’t so much solve the problem as work-around it by giving everyone their turn in the captain’s chair.
Here’s another thought: Everyone at the table takes on the role of a bridge crew member. But then you also have an Everyone is John-style cap system which gives everybody at the table control over one “slice” of the captain’s personality / skill set and the ability to bid for immediate control over the situation. Unlike Everyone is John — where the character being portrayed is literally suffering from multiple personality order — the goal of the table here is still to portray a coherent character; it’s just that the disproportionate agency possessed by the commanding officer is now jointly shared by the entire table. (Which makes it much more closely resemble the rough-and-tumble democracy of a typical RPG group where everybody usually gets a say in what the next course of action will be, but occasionally somebody will just charge off and force people to follow in their wake.)