If you pay closer attention to my post, you will see that I said I thought you could write that story, seeing as to the fact the characters in it are yours.
But I'd be happy to share some ideas for benefit of the KotOS Series.
1. I think Sir Sharp should be one of the ten NF recruits that investigate Militiregnum (and he splits up with the brothers after the crash). That would explain why he's there. I don't remember if there are any other NF KotOS, other than the Founders, Seton and Legoboy, but you can add them, too, if you find them. Of course, if you prefer to use original or other characters, who am I to argue? It's your story!
2. According to my notes, the Faction War began five years before thedude arrived in Militiregnum. Is that compatible with your story?