Well, I see that many weapons are under one ''family''.
For example, I once found an ''Axe of the Magus'', and the other time a ''Amazon's spear of the Magus''.
There are also ''xxx of the Imp'' weapons, and so on.
I'm playing a DK with two-handed sword ( warrior ) and my hero wields a spear ( most of the time ) and a shield ( survivor, with regular size so that the muscle don't get in the way <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" /> )
And I have the impression that you have more chances to get piercing weapons if you are specialised in piercing weapons... that's just an impression.
I also tested a hero with 1H sword with shield and DK with 2H sword... and most of the time I looted 1H axes and swords and 2H swords <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" />
Might just be an impression I'm getting. But it might as well be possible that the specialisation influences the drops... not sure though... I mean... I can't really prove it... maybe it's just luck.