One thing that always sorta... I guess not confuses me but bothers me, when it comes to Knight theories in Deltarune is that anything that isn't Dess kinda does not mesh with how the story is presented. I am not talking about the evidence itself here, but specifically...
That Carol is such a transparent "Character you are presently expected to think is the Knight as someone playing for the first time". Most of Carol's mentions portray her as being ominous and threatening, Alphys speculates that she's 'held back' by the police in CH2 (before the Knight would kidnap Undyne in the next chapter), the mystery caller in CH4 is broadly assumed to be the Knight by first-timers and it seems fairly obvious (circumstantially) that Carol is the caller. She's even 'investigating' south of town, presumably near the Shelter, in CH5.
She's also probably a red herring. The whole "Carol shouldn't be able to make it back to church before us" thing aside, she's never actually caught red-handed and it's all circumstantial evidence. She's an intentional red herring that is meant to soak up suspicion for first-timers, or at least that's how she's reading to me.
Which means that Dess, who is generally the character most people believe it is and has by far the most compelling evidence (all the Holiday connections that's shared with Carol+Rudy, how the Knight appears at the end of a chapter that's so directly tied to Kris and their trauma, the way their sword resembles a bat on first summon, even Dess being implied to be left-handed based on her room and the Knight's idle battle stance holding the Black Knife in their left hand, among more things that I don't need to go into detail about), shouldn't also be a red herring.
It just feels bizarre in a circumstance where it's not Dess, because that means there's two red herrings in a mystery plot that only needed the one. I can see Carol actually being the Knight, it's a reasonable subversion (barring the logistical issue of getting to church quickly enough, which can be resolved in a single sentence) that the semi-obvious red herring turns out to actually be real, even if I still think Dess is the most likely candidate, but someone other than Dess or Carol just doesn't really scan IMO. It's just odd to have a pretty obvious red herring, then a second more secret red herring adjacent to her.
This isn't to say that the alternate Knight theories aren't interesting. I think Rudy Knight genuinely does have its appeal, and honestly works with Deltarune's themes insofar well enough that I can only argue against it specifically on the lack of proper build-up for it. Noelle Knight may not be viable, but I think there's potential in it from a story-telling perspective. I think Kris+Noelle Amalgam Knight is conceptually insanely cool, albeit not workable at all in the current narrative structure (logistics aside, the thematic groundwork is not laid well enough for this). Asriel Knight may fail the sniff test now, but I can see why someone would be interested and it wasn't historically the worst guess before the Holiday connections started becoming transparent. I was an adherent of Kris Knight back in the day, and I'm happy to see that I was proven right on everything except them being the Knight specifically (and I guess Kris making the computer lab Dark World, but that was never the part I cared about when it came to Kris Knight). Alvin Knight was actually a pretty neat theory back before CH4 did cataclysmic damage to it. FRIEND/Gaster Knight is probably just people getting a smidge too theory-brained with mystery figures, but even those could work out if the story was written from the ground up to support the reveal. Even Papyrus Knight, a theory I generally shit on any chance I get, could be at least fun in a world where it was properly prepared for.
I just don't think they are good theories any more. Further down the line, once the dust settles, the true identity of the Knight is revealed and we have the top-down view needed for fans to really dig into things properly, I think these alternative Knight ideas will make for compelling fanworks, some I might even like to a comparable level to the actual work. But a theory inherently implies consistency with the text and (in the case of ongoing media) a prediction regarding the story, of which these alternatives just (in my view anyway) broadly fail.
