I too liked BG 1's down to earth approach to companions including 2 Zhentarims, a Drow cleric and ranger from Rashaman who talks to his pet hamster. BG 2 as well, with Jan Jansen.
Forgive me my sarcasm but the companions in the original BG games also had their problems. Whilst I don't think the companions in BG 3 are great, I don't think BG 1 is an example of a game with good, down to earth, non "comic relief" companions either. If I was to use an example of a game with "down to earth" companions, I would have gone with Dragon Age 1.
Funnily enough, most of the companions in BG1 were actual characters some of the devs used in their DnD sessions way before the game was even in plans. Minsk for example is character which was invented precisely for these sessions as a half joke, but for genuine roleplay.
