I like this. The thought about downfalls or disadvantages is this: if the 13th crusade has not/very small downsides, why play any other list if it has everything?
I have to agree. The 13th Crusade doesn't need drawbacks... just as is gets no 'extras'.
On the single mark in the marked Chaos list: why? A Lord can have two marks (Abaddon has all/undivided). Chaos Gods work together.
Maybe I was getting the wrong impression. I thought this list was about giving World Eaters, Thousand Sons, Death Guard and Emperors Children a little extra. All other 'Marked Fleets' could be represented simply by the 13th Crusade if you buy the Marks.
Rename CMS cruiser to Renegade Strike Cruiser, Strike Cruiser tells me it is Marine, Renegade that it is against the Imperium. Not all renegade Marines fall to Chaos.
Or should we do a seperate Renegade fluff-list optional idea thing of sorts?
I think the Incursion Fleet is probably the best way to represent a renegade fleet.
As with the Strike Cruiser you're right. Renegade Strike Cruiser sounds better and is more flexible... with or without actual Marines.
I think of the Incursion Fleet like this: 13th Crusade + Extras (Light Cruisers, Renegade Ships) + Restrictions (Requirements for Cruisers)
This way it's the Renegades list that differs from the 13th Crusade basis, not the other way around.