2238 has "follower" scripts (for mercenaries, companions, slaves and some animals), not sure about SDK.
Their behavior is controlled via dialog, and also you can give them (but only all of them at once) some basic commands (like to attack or to move) with alt-click (or maybe it was ctrl). With a bit of scripting it should be possible to do anything Fallout 2 does and much more.
Party system with selecting particular party member like in BG would be more work.