As the post above stated, Rush attack and charm do wonders for such situations.
Charm is more suited for lower levels where your magic resistance isn't at it's full potential and rush attack works all throughout the game. I was pleasantly surprised when I found out that I can "fly" using rush attack.
a caster that can melee and beat the ever loving crap out of you. A finger-twiddler can hammer on you.. hard.. I mean... Whiskey-Tango-Foxtrot??
To address that, I'm sure there are all kinds of enchantments to augment physical abilities and whatnot, I wouldn't be surprised if some mage uses a telekinetic spell to make his limp-wristed slap feel like a bus running at full speed. Magic is cheating ,just like that.
On a semi related note, have you ever met a high level mage from the Dungeons and Dragon franchise?