Yeah, it could also serve as an achievement of sorts for the players, managing to convince the party members you really want to stick around even though they don't actually need to anymore. And Larian could build some companion quests with the option to either send them away or keep them in the NPC pool as the wrap-up. As a side-note, I'd love it if the whole camp mechanic had a bit of resource management to it, in terms of having food, water and such available but that's the simulationist in me talking and that probably won't ever be implemented
