Erfworld 119, page 107

[fendrin]

Well, yes; we already know from Jillian's account that she was popped as an heir. (I suppose it's possible that she's lying, but I don't see any particular reason to think so.)

Nor do I, that's why I said it would be no surprise to use.

We already know that you don't need to be a royal to become a barbarian: "...if it looks like we're about to get crushed? I'm planning to send you and the other casters into the Magic Kingdom. When the city falls, you'll be barbarians."

Then why was Stanley being promoted to Heir Designate significant? I think Parson was assuming that Stanley would still be alive when he would send the 'casters to The Happiest Place on Erf. He had already made his deal with Charlie, so Stanley's survival is the likely outcome (based on Parson's info, at least).

I'm not sure how that follows.

It follows because Ansom and Vinny did not assume that the leader of a barbarian faction was a royal, so either non-royals becoming heir (probably as a last-ditch effort to save the side) is frequent enough to be the default assumption, or there is some other way to become a barbarian other than losing one's cities. There is no other way I can think of to reconcile Vinny and Ansom's doubts about Jillian being a royal with the apparent 'rules' for becoming a barbarian.