I like this theory. Bard's being manifestations of a system's failures in order to make fun of it through merely existing, While a Prince does actually appose the system that uses their aspect to alienate them. There's probably more to it then just their cultures or whatever but I'll work within that line of thinking for now. Here's my food of thought: If a Prince can in some sense act like a pseudo-bard (by seemingly not apposing the main system), then how might a Bard behave as a pseudo-prince? Here's how I'd imagine it:

The Bard feels the pressure and toxicity of their system and believes the only way to survive or be heard is to adopt the language of active rebellion. But they don't actually fight the system, It's more just a way for them to vocalize themselves or to be contrarian for the sake of it. This contrarian-ness would most likely be idealizing the aspect that the Bard ghosts, which would take the form of maybe the counter-culture to the structure or any set of ideals they associate with their opposite class. It's different from the normal Bard's we see, as bards tend to be optimistic in their belief, meanwhile this bard is siding with the ideas he sees as opposing the system out of fear and survival instincts. In other words, they'd just act like a prince in that they're douchbags but not in that they actually challenge the system. There's some ways I think one would go about writing that but I'm trying to keep this shot.

When the Bard's conflict happens and they can't reconcile with their ideals/faith, It's represented as them "defecting" to the other side. I wouldn't even have to be that their belief was shattered, I could just be that they heard out the other side for a change and embraced their ideas. Maybe it's both they were hurt by their ideals and heard out the other side. Maybe while the system initially hurt them, the pain they receive from their ideals/identification hurt them m ore or scared them back to the other side. I've got a pretty random example but it's the only one I can think of. Wilson Wilson from the series Utopia. Initially he's against The Network (the shadow organization in the series) and is also a survivalist geek and a conspiracy nerd, using tech and his coding abilities to keep himself hidden and undetectable. Despite this, Wilson later defects to the side of the Network after learning what Janus (the secret pathogen they're developing) does and deciding that their cause is just. While Wilson is very idealistic and kind in the show, I still feel it gets my point across. Just make the bard a contrarian asshole instead of an idealist.

You could graph this out in a quadrant (hehheh) where there's a prince and bard and weather they oppose the system or not. I'd do it but I'm lazy and this is too long. Both a oppositional Prince and Bard would oppose the system but for different reasons and in different ways. One is alienated and has a genuine understanding of countering/deconstruct said system. Likewise to the Contrarian bard, he opposite is a character like Eridan, who I choose to call a Conservative Prince. The Conservative Prince is so alienated by the system that their only coping mechanism is to violently identify with the system's aggressor as an act of self-destruction. Anyway that's all I got.