A thief should tool an assassin, in pk, both players being skilled.

I know when my most powerful assassin, Lokrin, clashed with a thief, he only won because he was hasted before the fight and the thief only had one scroll to slow him with. After that my uber-gear made him flee, but he still managed to rob me. A non-hastened or less well geared assassin would have been toast against that thief.

Mainly because thieves have blackjack, steal, scrolls and maces.