Play both sides against each other if possible (offer to help the K/M take out the Sorc and Vice Versa). If you can get them both going in an all out fight while you "wait back until their defenses are down *nudge nudge wink wink*", you might be able to pull off a GWW+stun/quiver on both if you're quick about it, they're both visible and not illusioned, and they're close together. That's a lot of ifs :eep:
Without the ability to take out illusions and defenses, you're fighting an overwhelmingly uphill battle.
The only other thing you could do is start running, and keep running if they go after you individually (if you get away from the first Time Stop/Improved Alacrity which will reduce you to paste) - I suspect if they both work together against you, you'd be doomed. Invisibility potions and non-detection are a must, even if they only buy you a round or two.
Bring a few of every single protection potions/scrolls you possibly can, a bunch of Protection from Magic Scrolls (Consider using these offensively if that can be done...), and pray to god that they don't get off an imprisonment. Items that confer immunitys to certain effects will also be necessary.
I wouldn't expect to win in that kind of situation, but I'd still try it a few times. Make it an endurance fight as much as possible since they can run out of spells, you can only run out of HPs once