I've recently been playing with Oscuro's Oblivion Overhaul - and I've been loving it. However, one thing that REALLY grates me about the entire thing is the pathing of ranged enemies, mages in particular.
Now yes, I understand the logic behind the descision to make them run from a melee engagement - they're ranged, therefore they stay out of range of a melee enemy. However, even as a battlemage - someone who CAN fire spells, I find their erratic, CONSTANT running an absolute PAIN to deal with - it's not like half the time they even deal that much damage, so it's not a question of difficulty. It's just plain FUSTRATING to have to chase down a mage who will not stand still no matter the circumstances, and who moves too erraticly to actually hit with a fireball. It gets to the point of fustration where I just turn on godmode and noclip so I can kill them without wasting an unreasonable amount of resources on a mob which, by all means, isn't actually that strong when it comes down to it.

I realise that OOO alters the pathing of different kinds of mobs in combat, which is why I'm asking: Are there any mods which alter this? I'm fine with them running occasionally, I just really want them to stand still for once! >:o

Don't think there's any mod changing that, but is it really OOO's doing? I remember being annoyed by mages running around even with vanilla. Anyway, I'd say deal with it. It's annoying mostly at lower levels when the PC is still slow and doesn't have much options. As soon as the PC can mover around faster and/or make spells with area of effects etc. it isn't much of an issue IMO.