It's not only the wizards, but all his bodyguards as well. I'll admit they were 3rd to 4th level bodyguards wielding bastard swords one handed. With his flurrying, he was disarming one per round and grabbing their swords.
Yes, a wizard is weak in melee, so does this mean that effectively a wizard should never try to use a wand, rod or other spell item in combat? Because it will just end up being ripped out of his hand.
I think one thing that bothers me is that the monk does not need a minimum attack roll. Any roll is a disarm attempt. Say a low level monk rolls a 2 and adds +7 due to feats and stuff. This doesn't even Touch (let alone hit) a flat footed peasant, yet the wizard has to beat this roll at -4 or lose his wand (which would surely be harder for the monk to hit in the first place than a flat footed peasant).
Perhaps a touch attack should be required first?