Plenty of them, usually in the low magic end. . . .but the rest fall into the "Stab them in the back and casters die too."
Like, in conan, casting is usually very nerfed, but even the earth shaking caster types seem to eventually blow it, and either combust themselves or get beheaded/impaled by Conan or some other non-caster.
Similar in Lankhamar.
In Thieves World casters generally weak, other than the Janet Morris stuff, but even there they're mostly dead. (Mostly dead due to Tempus' or his sister killing them admitedly.)
Cook has super-super-mages. . . and somehow the non casters seem to outthink them and either dark knight them or get in their heads and send them off into a self destructive tizzy.
Erickson seems to have a similar tone actually. . . .and actually, at that tech level, there's a lot more leveling. . . Fiddler and a load of Moranth munitions takes no crap from any mage. . .and I can think of a number of instances where mages or highly magical creatures were either killed by one non-caster, or dog piled by a horde of non-casters. (BTW, the game system in Erickson in GURPS, I found out in an introduction to a Cook book he wrote a while back.)
I think, in the end that "High Magic" tends to have a number of leveling effects, which in fiction are so common they could almost be called "standards":
1) Casters, as they get more powerful, tend to draw powerful enemies non casters never have to deal with.
2) due to #1 casters get more and more paranoid and isolated. . .non casters have armies of friends to draw on.
3) Somehow whenever magic makes a mage omnipotent and omnicient, they combust themselves, at anything below that, you can kill them by stabbing them in the back.
4) Anti magical materials exist for non casters to pick up and use, that a caster would never touch.
5) Magic items often level the playing field.
I think Erickson is a perfect demonstration of the effect I'd mentioned earlier. . .how often in scenes with the Bridgeburners is Quick Ben either: Menacing someone with his magic, but not actually doing anything, or hiding and observing, or engaging in subtle magic that doesn't even become apparent until the end of the book. . .
That's how casters seem to work out in play. . .they are massive "Potential" power they use to scare people, but using that power will make them weak, so they horde PP like their life depends on it. . .and if they engage in a public life they get hounded to use their power or targeted by enemies. . . .
If you're playing a classic "Dungeon Crawl" that never ends, and this is just about spot damage potential, I cannot deny that magic tops the pile there. . . .out of combat they tend to have a lot of potential too, but yet somehow in a roleplaying centered game, the casters seem to ALWAYS have serious disadvantages. . . .generally people fear them, or are suspicious of their motives. . . .take a look at how much crap Gandalf takes from everyone about that, or Merlin, or Ben Kenobi. . . .nothing is more amusing in roleplay than playing the super 30th level mage and telling the king he has to do something about the demon gate about to open in the palace basement, and in response being forbidden to do anything about it and escorted out of the palace under guard. . .do you fight the king's men or allow the demon gate to open? Either way everyone is going to end up hating on you.