OpenMW is very true to the original, the intention is not to change things like the combat system. There are some modifications that go for this, but the more awesome ones need the big engine hacks that are incompatible with OpenMW.

Combat btw becomes a lot less tedious if one knows that chance to hit / block / evade depends on fatigue and fighting while exhausted is a bad idea. Modern games have sophisticated cues to make such effects known, like audible heavy breathing noises and visible screen bobbing and blur effects, etc. MW has no such cues.