Brand new ToEE player here. Love the game so far and really like the Co8 mod. Good job with that. Still on my first playthrough and I'm noticing that Spugnoir and Meleny do not suffer negative repercussions from using weapons that they are not proficient with. They both have only the Simple Weapon Proficiency feats. For example, I can equip Greataxes and Longbows to both Spugnoir and Meleny and their attack rolls never drop. These weapons still include a red border while in their inventory indicating no proficiency. I'm not sure if it's the same with armor that they are not proficient with. I'm not sure what wearing armors without its respective proficiency even does.
FinaLfront, welcome to the forum. I'm glad that you are enjoying the game - it is a superb game! This is a known bug. There's nothing that can be done to fix the bug because this game mechanic is hard-coded and would require the game's source code to be released as open source (which isn't likely to happen any time soon, if ever). Any NPC in your party can use any weapon (even exotic weapons) without suffering the normal -4 penalty to hit for not being proficient with the weapon. It somewhat makes up for most recruitable NPCs being worse character builds than PCs that you can create. I like that NPCs in your party can use any weapon without penalty - it allows NPCs to use weapons that your PCs would never normally use or that you haven't prepared your PCs to use with the appropriate feats.
I played a full game back in 7.4 with Meleny without noticing this. I guess people that haven't played D&D 3x for over a decade may not have the proficiency lists memorized.
I never realized that either. Probably because I never even attempted to use a non proficient weapon. Cool to know though that now any of those powerful exotic weapons that are found don't just go to waste or need to just be sold.
Well, I'm completely lawful when it comes to D&D rules. Even though they can use off proficiency armor/weapons I still refuse to do it unless they have the required feats. @r0gershrubber I've been playing 3.x since NWN1. It wasn't that I didn't have proficiency memorized—the exotic loot and armor being lugged around in inventory wasn't displaying the red off proficient bordering.