FOC while using coven formations

So here is what I want to do. I want to have a list where i have lots of bikes, 3 units of 6, and then a couple boats with warriors for my troop choice slots and then i want to take a coven formation or 2. I was thinking of taking my grotesque formation and then the hammy, talos, and talos formation. Do i need to have another HQ to complete my FOC for my standard DE or do the hammy's count in the formations? I want to be able to use the troops as objective grabbers if need be since from what i gather, they trump other objective grabbers as troop choices.

A model cannot belong to more than one detachment so the Haems in the coven detachments do not count in the CAD. So yes, you need another HQ.