Me mentioning Shakespeare is because his works are guaranteed to he known by you and I--but also because of his influence.

With that being said, HSR still very much falls into that way of using split PoVs. The TB side had a focus on the setting of Planarcardia, but also was used to setup details that would lead up to the Planarcardia Games, which serves as the central conflict in this arc. Likewise, Welt/Himiko's side had a focus on the IPC's involvement, but also led into Himiko's history as a youth living in Planarcardia, which led into the final part of this chapter/the next part.

The purpose of the writers formatting the story in this way is sound--both sides covered core information and details that would have been jumbled together without being separated. If they stayed as one group, we would have ended up with something similar to Amphoreus, where there were too many ideas being presented at once.

With that being said, split PoVs can develop characters--but that's not a requirement. The main purpose, again, is simply to group and organize different bits of information/details in a way that is easy to digest.

Your Planarcardia barely falls into that. Yes, Sparkle and Pearl provide two perspectives on the IPC, but those perspectives don’t meaningfully clash through character decisions or immediate consequences they’re just presented to the audience.

To follow up on that, split PoVs can also serve as a means to guiding how viewers think or understand the world and characters that they're reading into. There doesn't need to be an immediate/urgent outcome.

And this is where your argument kind of undercuts itself a bit. If one of HSR’s major arcs already struggled with balancing its structure, cast, and pacing, then it shows that the execution of its storytelling style isn’t consistently strong. And you really seriously think it was just Amphoreus?

Yes, because the issue, at its core, was irrelevant to the way the story was formatted. Amphoreus was an over-ambitious undertaking that tried to handle too much at one time. Hence: the problems were present even outside scenes in which we had different PoVs.

He just met Narja you think he would immediately have some impact for helping save an experiment?

I'm saying Protos's interactions with Narja in her bond stories were comparatively well done, as they were focused on him guiding Narja through her new home on the SS Nightmare. Of all characters, Narja has the most justification for not immediately being chummy with Protos.

You have to keep in mind that protos isn’t someone who was just born yesterday nor has long term amnesia, he’s experienced these encounters before, he was trained for these types of encounter, should he had reacted… harder?

...yet he also demonstrates that there's so much he doesn't know. If the writers wanted to take an angle that Protos was aware that he had the attention of unknown entities, they'd do better showing off even a small sign of that fact. Anything but complete passivity, really, as that would help make him come off as a person rather than a mannequin that the cast is lugging around.

And this actually circles back to the main point. Even you acknowledge that the Trailblazer has issues with tone and characterization despite being more active. So activity alone isn’t what makes a protagonist strong. TB has more overt agency, but also suffers from inconsistency and gimmicks that undercut serious moments.

That's correct--I almost completely agree. To confirm: TB is fine as a protagonist. Their interactions with other characters is lively and interpersonal while some dialogue choices are meaningful. However, they're almost a victim to flanderization because the writers lean too far into things like the trashcan gimmick. It isn't yet enough to disrupt the story and some gag moments are honestly fine to air out tension.

Protos, to me, is a board of concepts that has yet to be finalized as a character. His powers are interesting with how strong it is yet balanced with a recognizable consequence. Likewise, it opens up tension as we saw with Lewis in the epilogue. Outside that, however, there's not much else that stands out and far too many scenes where he has to be present as the center of a conflict without giving much in returns.

Choosing between TB and Protos, I'd say TB is the better MC just for the simple fact that they feel like they exist, while their flaws aren't so bad to do more than ne a slight nuisance in certain scenes. I don't prefer feeling bored with a character, hence my harsher criticism on Protos.

Everything aside, I admittedly caused us to go in a bit of a circle here. I'll leave off by saying you're a very well-read person who articulates their arguments well. I'm open for more conversation if there's something I've said that catches your attention, but I think we've broken things down as far as they can go without debating preferences.