RTS FPS combo, where one person gives orders to the units who are then played by players. Maybe this already exists idk
The map design is amazing, game runs and looks great. Highly reccomend
The way it's made requires a lot of dedication -> gathering everyone, organisation to communicate can be tricky particularly if you want realistic kind of comms: teamspeak is still required (I don't think there's a realistic mod for Arma 3 compatible with Discord).
Nevertheless, Arma 3 has everything you need:
Big maps (open world)
An actual map (I am talking about the paper/GPS thing) -> with actual elevation information on it, etc.
Complex strategies and tactics possibilities
Communications
Vehicles: helicopters, tanks, cars, trucks, planes, boats, etc. etc.
A very WIDE set of weapons of all kinds: turrets, firearms, launchers, mortars, etc. etc.
All this adds up to the need of coordination, planning, preparing strategies, primary objectives, secondary objectives, backup plans, backup plans for your backup plans, etc.
1) Total War series — it's not FPS per se but there is the idea of managing the macro situation (resources, where armies are, developing cities, etc.) and then when you actually attack another army or lay seige, you have more of a tactical view where you direct the action.
2) The original Rainbow Six (and maybe some of its immediate sequels). You would plan out exactly what you want every one of your special ops guys to do (e.g., when I give the signal throw a flashbang into this room) and then you get to play as one of them. Not sure if anyone has replicated this yet!
Honestly, NS and NS2 the commander was a fun position. You play to upgrade your units, grab resource nodes, and expand influence, while trying to direct non-compliant troops. (Really throws in a wrench to your RTS when you can't get your soldiers to do something you need). Another aspect is in the smaller team dynamic of NS, one or two good troopers can have an outsized effect on enabling the commanders gameplay.
Empire mod gets around this by having larger teams (15+ vs 15+) with vehicles, upgrades, weapon customization, tech trees, so it really plays like a war where you need to counter what the enemy brings to the field in terms of tech.
Empires mod, quite detailed FPS RTS. Even has vehicles, tanks, APC, resource nodes.
It's been awhile since I played, but there was still some development on it a few years ago.
Downside is its a bit older. (2008 release)
has been around since March 2000, and currently free to play