I have seen people complaining about combat issues but I didn't have any. Well, maybe I was just lucky. If you want to bring a standard game mechanics and function from a Main into your custom mod then you are in a lot of trouble. Because, it looks like a level specific scripts and generic game mechanics are pretty-well-messed-up-all-together. I spend something like 20-30 hours, sorting out scripts and dependencies while making the UnderSiege. If you want to create a mod that provides playable content and quests then you are welcome to expand UnderSiege with your own level. If you want to create your own stand-alone mod then you are welcome to explore the UnderSiege and see how it was made and use it's scripts. Generic game mechanics should be located in Global_* scripts and mod specific stuff in UnderSiege_* scripts.