Is it possible to make a battle forged list with just these "Navis Imperialis" units?
If the breachers and voidmen have this rule:
Shipborne Personnel: If your army is Battle-forged, this unit cannot be used as a compulsory selection in a Detachment (e.g. as the only Troops unit in a Patrol Detachment), unless that Detachment is a NAVIS IMPERIALIS Detachment.
Which makes me think, ok, if I just take a Navis Imperialis detachment they can be the troops, great.
But then the only
HQ, the cartographica rogue trader, has this rule? :
Master and Commander: If your army is Battle-forged, you can include a maximum of one Cartographica Rogue Trader model in each Detachment in your army. This model cannot be taken in a compulsory Battlefield Role slot.
That seems like it would render the rule on the infantry pointless. What gives? Can you take them as a list by themselves or not? If not, why do the troops have that rule at all?