There were several updates (
release notes) for the original disk version of the game (1.29). There were differences in the difficulty levels, with the 1.32 patch making the bosses and some regular opponents easier on the easy difficulty. I didn't change the difficulty with the same character, but a survivor on hard was noticeably harder than a warrior on normal, at least.
When I first ran into the orc drummer I couldn't damage him faster than he could heal, but he couldn't hurt me, either. Meeting the travelling merchant on the path to the cursed abbey, I bought a better sword (with a Stun bonus, as well), and went back and easily defeated the orc drummers.
I don't think the download version did anything to the opponents or difficulty levels. Do you just have a better build, having played it before, or maybe a couple lucky equipment drops helped?