More often I would mix in telion in my Kantor army. In reality I think they should have neutralized the characters chapter affiliations and made them generics. Put in character rules and abilities balanced against the Chapter tactics in the game so you don't have to stop people from picking the theme they like in a SC. They just get wrapped up too much in fluffing out chapters. The book should be the generic space marine book and put fluff characters in the supplements.