Nothing is preventing the k/m from having grandmastery in weapons and using staff of magi/staff of ram/regular quarterstaff, and smackin the crap out of the sorcerer. Switch as applicable. Put SoM and SoR in quickslots, and go invis as needed to avoid targetted spells and when the sorcerer protections come down smack him across the screen
Or he could use something like Celestial Fury and keep the sorcerer in stun lock. No matter how high of a level you are, you will always have horrible saves and it gets doubly dangerous with greater malison. I would also like to point out that the stun effect of celestial fury works independent of damage, so just whack away doing no damage, but secure in the fact that he won't either. Oh yes, the monk.
The monk's stunning fist is in my experience, weaker than the CF. First, it only lasts 6 seconds. Second, it's downright annoying (and deadly) to keep hitting that special abilities button. If you try to use the katana of doom, your attacks drop to 1. No, I think any smart PvPer will try to take out the monk first. No telling when an unexpected QP will take you out. After that, just whip out the Celestial Fury, and get to business.