Well if they go the route of SM each kabal, cult, and coven will have something like a doctrine a stratagem and a unique WL trait. but that would be a lot of different rule sets. Not to mention the army wide generic WL traits and stratagems. But they aren't exactly opposed to doing such. It'll probably be one page for each kabal, cult, and coven ... A page of generic stratagems, and a page with generic WL traits and relics on it, then a page of upgrades and wargear followed by updated unit data sheets. Then points values. Fluff will be the first half of the book.