I've installed GOG's M&M6 and applied the GrayFace MM6 Patch v1.6. I have a question regarding the number of NPCs.
I currently have 2 NPCs in my party, an Instructor and a Scholar. In the Abandoned Temple of Baa, there is a quest to find Angela. I've found her and she immediately joined my party without me needing to banish one of my NPCs! There are arrows beside the NPC window to indicate that I have more than 2 NPCs in my party!
Is this a feature from the patch or has it always been available in the game? When I played it many moons ago, I don't remember my party having more than 2 NPCs.

You can only have two hired NPCs, but quest-related NPCs don't count towards your limit.

Oh ok. Thanks!

There's one very annoying semi-exception to this - later on there's a quest (might be optional, depending on your party) which requires you to hire 2 specific NPCs, so while you're only hiring them for quest purposes (they are otherwise useless), you will have to fire your Insctructor. I spent about an hour yesteday looking for a new Instructor to replace her after I was done with the quest.
But yeah, the 'rescue this chick from the dungeon' quest NPCs don't count against that limit luckily.

I've been there.. I know that frustration, but I still couldn't replace my NPCs (a Pathfinder and an Armorer).

Oh yeah, I remember that. Well, one can always save-scum to get the desired NPC after that. (If you don't mind that sort of thing :P) The only NPCs I like are exp-boosters. And a bard to help with Light Magic mastery.

I usually go with a banker and scholar - XP boost, unlimited identification, and a little bit of extra gold.

Right now, I've picked up a Merchant (combined with the Merchant skill of my Priest, it really helps save gold for training, which is also cheaper thanks to the Merchant) and a Pathfinder. However, I may later exchange the latter for something with a nice XP boost.