If I remember correctly, I think the NFIP policy that was issued first would be honored by the NFIP in the event of a loss. The second would not.
As far as your forceplacement, what type of policy do you use to forceplace? If MPPP, you still have the same issue, as MPPP policies are NFIP. If you use private insurance to forceplace, your need to have a concurrent coverage endorsement in order to make loss claims. The concurrent coverage endorsement works like coordination of benefits on a health plan, where the first policy has to pay then the private policy would pay so much after that.
_________________________
I can't herd the cats anymore, so I just set up the electric fences and let them fry when they stray out of bounds.