My brother got Stellaris on Humble Bundle and we've been playing with two other people *_*
wait I can't take credit for that
On our second run the Khan woke up again, once again *directly* next to us. We had to surrender again, but we were better prepared and were able to ever-so-slightly delay him at a couple of key systems. See, being a satrap isn't actually very bad at all, but we wanted to preserve our federation. Even if we weren't in it.
I'd accidentally let the Subterranean Empire spawn, but had peacefully vassalized them. I released them, giving them full Federation membership. Then our envoys desperately buttered up a megacorp until it agreed to join (it was easier once our hive-player had to surrender to the Khan). So soon the Federation was just me and these two AI, with the horde swelling with the forces of the three other players. As their levies smashed through my defense, I surrendered as well.
A couple years later the Khan died, mere moments from crushing the megacorp's homeworlds. His successor released everyone, embracing egalitarian ideals. Our trade Federation had survived, barely, without us being in it. We begged our way back in (it took a lot of coaxing to let them accept our hive mind player) and now things are looking pretty gravy.
A nice thing about Stellaris is that there's absolutely no need to backstab these valiant NPC empires, and we have no intention to. Two of us would feel *awful*, and the other two don't care. We will prosper together!
(We do kinda dominate Federation politics of course, by colluding as players, but it's in the best interests of all involved. The AI can be very dumb - like refusing to surrender to the Khan <3)
Stellaris