Arcanum's Multiplayer implementation wasn't very good. When I first bought the game there was lucky to be 20? people on. I'm being generous because I actually remember about 5, and this is when it first launched.
The MP mods they gave you were no where near the quality of the Single Player mod and we wished they gave us that.
However, having done some SP and MP mods in NWN I now know how different those styles can be - namely you don't need to take a systematic approach with SP and you can "cheat" on it to take short cuts with problematic scripts. To make a SP in this system MP one needs undue all of that.
Aren't some of those games strictly or mainly MP? ST:Armada comes to mind but I may be mixing it up with one of the other ST's. Ahh, Homeworld, its hard to believe its being forgotten. A groundbreaking game in terms of graphics and experience back in the day.
I'm shocked to hear Kali is still around. We used that in the '90's.