Assuming SE either wants to push housing towards FCs, or has hard numbers to back up why they are splitting it this way. I would be very surprised if the FC wards don't fill at the same rate as the personals. A 2-person FC is just as valid as a 50-person one. The 30 day requirement will deter people/bots making new FCs, and by the time 30 days passes, Ishgard will all be claimed.