Wow nice update, wasn't expecting Caesar as heir at all though it is entirely appropriate what with the name and all.
There is some actual heavy stuff to speculate about in here though...
Basically it's getting me thinking about freewill with regards to Erf. We already know that existence in Erf is a privilege to ordinary units and a "right" of Royals and Overlords, basically they are kinda more like gods than kings. They can't be disbanded (as far as we know) unless it were done by the Titans themselves and though Erfworld provides the mechanics of the order they can pop units as they choose, or at the very least guide and direct the natural popping of units on their side, and of course end the existence of their units with a thought.
But now we see that even Royals aren't totally free, not only in the sense of restriction of resources but in the sense of suggestive forces like the natural thinkamancy on troops and warlords within a side, Jillian is naturally bent to think like a Royal no matter how hard she tries not to, and Royals are meant to lead sides that's how Erfworld is apparently designed.
But what of nonRoyal Overlords? They aren't bent to think like Royals, we may not know enough about Caesar (least I'd have to reread his lines in a new light, still he's not overlord yet...) but certainly Stanley and Wanda don't think in the same way Ansom did (I take Ansom to be the stereotypical royal unit) and though Charlie's an enigma he no doubt doesn't think like a royal, though that might just be him being Charlie... one piece of evidence is his tremendous commercialization of warfare, beyond mere mercenary work.
The nonRoyal Overlords seem to be free, actually free, at least within the common bounds of fate, meaning they have at least the same freewill that we have (illusory as it may or may not be). Not to mention so far that the nonRoyal Overlords are the only ones so far to have gotten Arkentools, I include Wanda in this as she's not technically loyal to Stanley and now she has her own army. Considering the structure so far of rank in relation to personal freedom, then these nonRoyal Overlords might well be higher in rank than Royals. Though that "higher rank" is more likely due to attunement with the Arkentools than just having been promoted from ranks to heir designate. Not to mention that wouldn't include Wanda and I doubt Stanley would make her his heir.
Parson is, of course, in nearly every sense of the word, a wildcard. I have no doubt that he could be essentially anything in Erfworld. Well, maybe with the exception of being athletic.
Anyway that's my wild speculative theory, it may be entirely that Jillian was just battling internally against her desire for revenge against Stanley and her rejection of herself as Royalty (and seeing how practical becoming Queen of Faq will play into her taking out Stanley).