It also shows a separate percentage for siege units, as those are easier to hit. Imagine being inside a tunnel with a small hole, and snow falling through it! Here's a small list of some of the cool stuff that might just give you an idea of how much love and polish has gone into it:
The list of enhancements is incredibly big, so you'll have to excuse us if we don't bother listing it all or creating in-depth documentation that covers every single feature in detail.