Anyway from a 20+ year old LL post by nefarious I found some details on AI parameters and what they do
Quote
PinHead
The first time a pinhead comes into melee range he will automatically attack.
1. Chance to attack (when within melee range)
2. Delay (frames) (par1 fails)
3. Chance to approach (when outside melee range)
4. Delay (frames) (par3 fails)
5. Chance to use SK1 rather then A1 (par1 succeeds).
6. n/a
7. n/a
8. n/a
-------------
BaalMinion
Chance to attack (when within melee range)
Chance to approach (when outside melee range)
Chance to use SK1 (par1 succeeds)
Delay (frames) [par1 fails, par2 fails]
n/a
n/a
n/a
n/a
Urdars in melee range he has 97% chance to attack, 3% to delay for 7 frames. At range 95% chance to walk to target, 5% to delay for 5 frames. And he has 70% chance to use smite instead of normal attack
Lister in melee range has 90% chance to attack, 10% to delay for 17 frames. At range 85% chance to walk to target, 15% to delay for 17 frames. And he has 50% chance to use smite instead of normal attack
This still doesn't really explain everything, and maybe a followup post does;
Quote
First of all, AiDel is used as far as I've seen only by a few Ais that don't have a stall parameter (SandRaiders etc), here the game reads the stall time from this column. However most monsters have hardcoded range and delay values.
I'm not entirely sure how this works. There's no stall parameter as a general column in the data files (sand raiders have nothing different than other monsters), all monsters have aidel and its usually 15/14/13 in norm/nm/hell (true for urdars, minions, sand raiders) but I understood this to be disregarded, hence the 15 frame delay, which is like he said.
but if lister's AI works this way, it might use the aidel value for baalminions, maybe it uses the 13 delay instead of 15? That
still doesn't explain lister's apparently faster attack, since it sure looks like ~16 fpa but that would make it ~20 fpa
The best guess would be that its from the latter part: minions have a hardcoded delay value that isn't in the game files, just in the code directly and overrides the normal attack delay and makes them attack more rapidly
If lister has something like an ~8 frame delay instead of 15 frame delay, then he could be hitting at ~15-16 fpa but have a 10% chance to pause for 25 frames on each attack, while urdars have just a 3% chance to pause for 22 frames on each attack.
Unless something is overriding lister's ai delay I don't see how he could attack that fast, and maybe I just got unlucky with him pausing a lot more than expected