The combat in Fallout 1 and 2 is one of the main things that turned me off of the game, and I think it would need a lot of improvements to even survive, nontheless potentially dooming the franchise by causing all sorts of lost sales from people who don't do research and just assume that the next game with Fallout in the title would be a niche thing.
In Fallout 1/2 the AI is just simply too stupid to be trusted with automatics. When you load into a encounter zone the majority of the time it will place them right behind you, and they will unload directly into your back, both wasting all their ammo and causing a whole mess of problems for actually trying to fight the enemy. How did Ian survive as a caravan guard when half the time he sees a raider he shreds his buddy infront of him? Every NPC is like this, and for anyone who wants to have companions with minimal headache its down to semi-automatic weapons, but then there's a whole mess of confusion there.
There's limtied animation frames for each character, which theoretically would limit the weapons they can use to what they told you they were good at. The assignments for these weapons have some real headscratchers. Sulik says he's good with "Fist, spear, submachinegun", and indeed he has the frames for all of those, but as previously established he can't be trusted with something like a 10mm SMG, so you'd give him a 10mm pistol to start off with, right? Well he doesnt have the frames for a one handed semi-automatic unlike a one handed automatic, but he does have the frames for those one handed semi's that have the same frames as the SMGs. You can give him a .223 pistol, and really he does fantastic with it, but how did he manage to use that when he refused to use the 10mm pistol I handed him back in Klamath?
Im not sure if this is just something cRPGs suffer from, since ive not played Baldurs Gate anywhere near as long and deeply to get experiences like that, but the one thing I thought I would really enjoy about my modded up copy of Fallout 2: Getting a team of companions and travelling as a party, with the mods providing the sprites for having their armour show up, (Personalized too, Sulik had a cool tribal pattern on his combat armour, spiffy!) was really cut short by the amount of frustrating and nonsensical things you have to deal with.
Its not all bad, though. Tycho and Cassidy formed the blueprint of what has become my "forever" Fallout character, Alexander, and if any Fallout game could bring back a companion like them, I would be extremely happy. Tycho always had my back with his shotgun, and I gave Cassidy a sniper rifle and he dropped any raider looking to mess with us before he ever gave us trouble. Those two had your back in the wastes, and since I never gave them any automatics, they never blew me apart before I got a chance to get my rifle out of its sling. Good men, the both of them.