Well there isn't much proof. All we know is where ever they "go" there is a sudden rise in noble count and military strength. Also, look at Fontans size do you really think they can pull of a 16000 CS army. Also, almost 100% movement on almost 100% of the time is something to be wary about as well, eh?
Averoth was made up of 5 of the poorest, crappiest regions ever, mostly sub 150g income. And they managed to field 14k CS at their height, with 40 some-odd nobles.
Do not doubt what these people can accomplish.
