Crannogmen are cajuns
The Crannogmen are perfect cajuns:
They keep to themselves
The eat frogs and mud bugs
They live in a marsh.
Crackpot: The Crannogmen are rich, just stupidly rich. How? because Greywater watch is a mobile oil platform. That's right, the Crannogmen are cajuns, and like cajuns, work on oil rigs. They trade that oil to the free cities. In fact, before the doom, the Valyrians had electricity which ran on the Crannogman oil.
After the doom, losing their primary trading partner and seeing that the Targs were douche bags, they remained secluded, occassionally chilling with the Starks, having Crawfish boils, making reality TV shows about hunting Lizard Lions, and cheering on the Tigers.
PS, the crannogmen started the STTD,B chant.