I have a small group of friends that play a lot of Civ 6 together. It's usually 2 to 4 people, and we tend to play same team vs AI with stuff like shared vision/open trading.

It's not particularly difficult - but it's a very fun way to kill an afternoon because there's a lot of random shit to bullshit about, the play styles of different civilizations are varied, and the AI is dangerous enough that you do need to pay attention to early rushes and an AI can run away with the game occasionally if it gets a really good start.

The problem we've been running into is that we've played Civ 6 into the fucking ground and all of us agree we don't wanna go back to Civ 5 or Civ 4. We've been sort of splintering off into subgroups or solo play to find other 4x games that work well this way.

For skill reference - we play Civ 6 on deity and win a lot more than we lose. But we're not doing like, crazy high difficulty challenges or tiny maps where the AI dogpiles you immediately.

Game wise, things we've tried:

Stellaris is really expensive - the game really wants you to have a bunch of the expansions or else it's very weird. My impression was also weirdly same-y - like if you want to play Co-op, people need to play co-op-y races, so you can't actually really take advantage of the breadth of empire design - it's not like Civ 6 where I can play Scythia and be aggro while a friend plays a supporty, friendly allied civ. In practice this ended up being a pretty huge deal breaker for us - we don't want to have to agree by committee to play a certain subset of races each game. Stellaris also caused problems due to the lack of a turn timer - we have a pretty wide variety of "preferred game speeds" so we tend to compromise with a fixed game timer. Stellaris really wants you to up/down shift speed pretty regularly depending on what's going on ,and that leads to a lot of arguing for us.

Age of Wonders 4 had some promise but the turn based battles are divisive - some people want to play them out because they're losing battles they KNOW they could win if they didn't autocalc, but at the same time every real time battle is like... okay everyone else has time to literally go make a sandwich or whatever. Also, the multiplayer instability was...... very difficult to deal with.

AI War 2 has co-op now but the learning curve is insane and the skill gap across our group is huge - there's no challenge at all if someone in the group can handle difficult 8 AI and the rest of the group can only contribute on difficulty 5. The good player just completely runs the game. This is also another one where the real time nature really makes it harder.

I haven't checked out Old World in a couple years but my initial impression of that was "civ 6 but shitloads of weird, opaque rng around your leadership". I think a lot of my friend group would bounce off that hard, I'm pretty willing to sit through "roguelike rng bullshit" and even I found it a little annoying.

We did some Northgard and liked it but everyone kind of walked away agreeing that it simply didn't have enough variety to have staying power - it also felt better competitively than cooperatively.

Anyway - We're really not attached to theme at this point. We'd try literally anything that's newish and has a strong co-op mode. Any suggestions?