Why would you want Dragons, though? an Apache can effectively do all the same stuff a Westeros dragon can do, with the added bonus of just being a vehicle and not a savage, untameable beast that will eventually have to be put down before it turns on it's masters. And you don't have to hatch Apaches from eggs or wait for them to grow up, you can just requisition more of them and then wait for however it long it takes them to truck it through the dimension gate to the nearest FOB.