In the RCM, weapons did a lot more damage but armor was also better, which means unarmored horses and people died in a reasonable amount of attacks instead of surviving a dozen stabs to the face, while armored horses were at least as tough if not tougher then native depending on your weapon choice. However, it gave Nords with their axes a chance vs the Swadian Knights if you ordered the Nords to stand ground in a tight formation.
For example, the axes did piercing damage (because piercing goes through armor better then cutting and axes are historically good at penetrating things, which is why we use axes to chop wood.) Glaives did cutting damage for a swing and piercing for a stab, the same with swords. Swords did something like 32 damage vs native's 15ish, and armor had increased protection values to compensate. He also put most of the damage from bows onto the arrows instead, so he could simulate the effects of different arrow types, and made bows do cutting damage and crossbows piercing.
Ron is apparently an American professor teaching in China. He has mentioned that he has done extensive weapons testing versus various types of armors as well as significant research in that field (you should read his talk about the US Army studies of wounds in the Korean War). This made him uniquely qualified to write a Realistic Combat Model. However, I don't know if any mods that work with the newest version of M&B carry the RCM. I'll have to ask on the forum if he ever wrote a version of the RCM for the newest Native M&B.
EDIT:
Ah, I looked on the M&B file repository. Here is a version of the RCM for Native that is for M&B version 1.010/1.011
I have no idea what the current M&B version is since I haven't played it in a year or two, so install it with care. I'm fairly certain 1.010/1.011 was the last release before Warband.
http://www.mbrepository.com/file.php?id=1212