Clerics get 5 per level to offense and defense (I'm pretty sure, my cleric
never melees). However they get 4 per level to their weapon skills, where
as we get 5. We also get dual weild.

After level 20 where you start raising your max damage this seems to make a
biggere difference. My 24 cleric has NEVER hit for more than 13 with his
Bullsmasher (dam 6). Keep in mind he has a str of 108 vs Elfson's 97. I
tried meleeing same very green BB gnolls, and still never went over 13. I'm
not sure how the extra damage is calculated, but clearly the wis casters are
behidn bards in this regard too.