Yes for the split if you mean (sorry, skimming) Codename/Real Name pages.
As for the order for who gets the top spot, I think the obvious solution is to put the most current and prominent person who is carrying the title. (So Captain Marvel would have Carol Danvers at the top of the page, whereas Ms. Marvel would have Kamela Khan, Ghost Rider would be Robbie Rayes, Iron Man would presently be Victor von Doom -- as opposed to Riri Williams as she is technically Iron Heart) I think the qualifier for this should be that the "top spot" characters should be actively appearing in a title during the current year, as soon as they are not, they are bumped.
However, having a central focus might always work so it should be adaptable to include any characters who might be using the name concurrently (Peter Parker and Miles Morales for example)
Perhaps a better method of organization for the name pages, I think we could do a better job organizing it a little better. I think if we organize things by code name in each page it would present a cleaner look.
Carol Danvers is a great example. (and i'll use Peter Parker when it doesn't work as an example)
Top of the page: The Earth-616 version. (Presently) Identified as Captain Marvel
Then followed by a list of the most prominent codenames she has gone under. These would be organized by what code name the character last went under in their respective identities followed by a catch-all for random ones.
Under this idea Carol Danvers would be broken down like this:
1) The most prominent version of her (typically Earth-616, although I think the qualifier should be where they have appeared the most. So perhaps that will sort out issues with MCU/Comic book prominence)
2) A list of alternate reality versions under their current code name (Regardless of number, if applicable) So in this case, Captain Marvel.
3) The next most prominent code name (Ms. Marvel)
4) Third most (If applicable) (I guess this would probably be Binary)
5) Fourth most (I/A) (I'm suspecting Warbird in this case)
--- And so on for every major codename. I figure if they have 5+ alternates it warrants its own subheading ----
6) Powerless (if applicable), basically every reality where they have no powers or code name at all. (I think this is the next most logical next step as many alternates have no powers or operate on a legal name basis)
7) Other identities (A catch all for all of the random unique code names for the same character that exist across the multiverse that have five or less usages)
8) Biological Identity - Although I think a less abrasive identifier could be figured out here. But I think this will solve the issue of characters who are the same being only their name is spelled differently due to different ethnicity, marriage, alternate spellings, and even gender swapped. Basically, if it is supposed to be the same person with some different characteristics that change their biological identity in some way, they would go here. I can't think of anything specific for Carol Danvers, but I think this would help for someone like Peter Parker who has versions across the multiverse who have different spellings to their name (due to different ethnicity, existing in another era other than the "modern age" and so on) or genders, and even realities where they're not human (so realities where it's basically the same character only the dominant species is gorillas, dinosaurs, jeeps, whatever) which should cover all the anthropomorphic characters and odd balls. However, in the case where there is more than on of these alternates (IE: the multiple versions of Peter Proker) it should link to a disambiguation page for that characters legal name (So a disambig for Peter Porker) to clear up clutter.
9) Clones/Replicants/Impostors Etc. - Would be a catch all for all characters who are not alternate reality versions but duplicates in some other way. Clones, unidentified impostors (like the random Skrull Insurgents during Secret Invasion that are not identified by name) To be clear, this would be for anyone who can't be identified by anything else other than the characters name. So "Carol Danvers" is the only thing we could possibly identify them by.
On Movies/TV/Video Games/Other Media
I have never been much of a fan for giving this its own heading. Frankly I find it a redundancy since most realities usually identify that it's a movie/tv show/video game. Also, you know, it should be pretty obvious looking at the thumbnail.
This might cause some problems with the template limits on how many characters you can fit in a specific category.. Is that still a problem?... I think that if an identifier is getting too big (IE: Peter Parkers who operate as Spider-Man) once we've reach the absolute limit we have a link at the bottom that says "More..."
Which brings me to my next point:
Sorting/Order
Because it's always going to come down to which version gets more prominence.
Honestly, the reality index exists for a reason. Therefor, all versions should be sorted in the best numerical order possible for that version of the character. Earth-1, Earth-2, Earth-3 Etc.
The breakdown would list indexed realities first, then followed by TRNs.