A werewolf (that I am certain was nowhere near lvl 10) was able to destroy my lvl 10 PC. Eating through stoneskin quickly and getting through the DR of my gear easily. His damage output was quite good. This was a one on one, no summons or companion. Things might have turned out different is so, but somehow, I doubt it.
With a silver weapon, I manage to hit him... 2 or 3 times? So he had decent AC.
i was level 7 and had a barb rage going whilst shifted to boost my ab, the character hits fairly hard but that is mostly his str bonus tbh, point to note though is that any damage bonus on gloves is actually carried over to claw damage too, so a level 4 with alleyfolk golves found in one of the soloable quests gets d6 lycan +d4 glove + str dam which is significantly better than the base lycan.
As far as defence goes pve is often easy as there are relatively few +1 weapons about but as CB says when you do come up against one you really feel it, and have to chug those extra potions to boost ac bark doesnt stack though maybe if it dod then that would make up for the lack of a shield?