I've tried twice today to put together a post about armor types in the campaign. While re-reading them I thought that they tended to ramble. The I thought that the subject matter was dealt too much with a quest for "realism" in the campaign. It's something that I am prone to get bogged down in. So please forgive me if some of what I post is over the top.
In a related note, the more I write about making a game more "realistic", the more I realize that simple solutions can work much better than complicated ones. I'm gaining a new respect for Warhammer. Not WFRP, but regular old Warhammer the wargame, 1st and 2nd editions in particular. The idea of categorizing armor into Heavy, Light or None, actually works very well. So does cutting down the weapon list and having a category called "hand weapons" that includes most 1 handed weapons such as swords maces and axes. It seems to me that those rules, along with the original "Rogue Trader" 40k rules were designed to be used with small battle scenarios with a handful to a couple of dozen miniatures, rather than the pitched battles and scores of miniatures that these games have used for the last 20 years.