S'mon said:
I don't think we're that far apart on this, except perhaps that I (nowadays) tend to play NPC mooks with a little more thought to plausibility.
Fair enough.
In summary the PCs IMC have plenty of chances to demonstrate their coolness and Great Cleave hordes of mooks, but I play most mooks as somewhat rational - normally, once the hero has slaughtered a score or so of regular goblins in 2 rounds of combat, the other 180 may think twice about approaching him.
Well, there's nothing wrong with mooks running away. It's not like destroying your enemies is the only option. Driving them before you and hearing the lamentation of their women will work too.
If he was fighting the Sultan's Fanatical Death Commandoes in the Royal Palace it'd be different.
True. Mind you, if I was to run an uber-battle like the one I mentioned, I'd probably have the mooks _be_ a bit more fanatical than normal, if only to facilitate the sort of epic violence that I like.
The first few times the PCs fought orcs IMC, they were fanatical and threw themselves at the party with scant regard for self-preservation. This caused some comment at the time, along the lines of "why are orcs so stupid?"
The answer, which they found out at the end of a quest, was that orcs are spirits of Hatred. They spawn in the Underworld when mortals succumb to such emotions, and from there, they make their way to the surface world, where they plunder and destroy. One of the consequences of this is that orcs thus have a vested, subconscious interest in making the other races hate them. They never surrender, and engage in plentiful atrocities if given the chance. Even if a given orc gets whacked, he'll be replaced soon enough, if his killer hardens his heart to them. This doesn't mean orcs will never run away, but it does mean I can have them throw themselves with just a little bit more abandon at the PCs.
If the mooks were regular humans, then things would probably be different, and they'd either surrender or retreat after enough of their number had been killed. Mind you, bloody massacres of fellow humans would probably not be a regular occurrence IMC. That's what orcs and other supernatural foes are for.