Very very cool about Men of War. There are some things along those lines that I'm working on, although likely not with the same visual sophistication (ha).
In terms of multiplayer, PvE is the main thing I want to focus on. This isn't just some sort of random "do whatever you like" sort of game; there's a progression to things, and an endgame that sort of cycles.
I know that a lot of people love PvP, but then you run into the need for all sorts of anti-griefing tools, anti-cheat tools, and so on. Before you know it, you're installing rootkits on the player machines and it still doesn't work (cough Ark cough). Or you've got really strange concepts like Land Claim Blocks in 7 Days to Die. Or those sorts of insane interactions and spawn-campers and all that from DayZ.
To me, there are plenty of games about "are you better at killing me or am I better at killing you?" I really used to enjoy Unreal Tournament and Quake II. And Day of Defeat and Counter Strike. But pretty much all of those, past a certain point, were team-based games. To me one of the interesting things was finding out "am I doing the best on my team, or in general how am I doing relative to the rest of my team?"
Putting AI enemies and a PvE scenario on the other side of that rather than other human players is something I'd prefer, but then to keep that sort of scoreboard system for the human players. Heck, potentially having random "bounties" that only show up for a single player, and the player can aid the rest of the humans by doing that if they want to. Other players can either help them or can just say "good luck to ya buddy." That sort of competition-that-is-still-teamwork is something I really like. It's Gimli and Legolas in a lot of ways.