Can I first say I like this open discussion idea of yours? You're trying to create a new division of tsuba based on current knowledge. Which is exactly what the people in the past did as well. But obviously they had far less material to go on and were bound by tradition.
Regarding your fixation on Akiyama, I suggest you read Sasano's Japanese Swordguard Masterpieces. He actually goes into the current nomenclature of schools and where they originated from. eg Kyo-sukashi were first mentioned in "Honpo Token Koh" (1795) which references an even older publication "Muromachi-Kaki" - a publication that Sasano doubt ever existed. So he was very diligent and critical about how the naming of schools came to be. This is just one example, the other schools are handled in an equal way.
In the Toso Tosogu Shogaku Kyoshitsu (NBTHK published - translated by Markus Sesko), Fukushi Shigeo goes even further in dept on the origin of the naming of each school in his typical Q&A fashion. He usually describes what was believed in the past, what's the current view and how they arrived at that and even the uncertainties that still exist and need to be researched further.
So does the NBTHK scrutinize old view points and challenge them when they find new info -> yes. However their attributions will always be on the safe side, they will never go on a limb and are very conservative. Which frustrates a lot of collectors, yours truly included.
Were the school names decided by Akiyama? -> no, not even close I'm afraid. Maybe a few were, but the majority weren't
Is there room for improvement? -> certainly, but what you're proposing is exactly the same what they did - trying to catagorize tsuba based on common traits, which I think is the only way this can be done.
Does the NBTHK get it wrong at times? -> yes, they're human. You can easily find examples where they got it wrong. This is also one of the reasons there's now a quotum on the number of pieces put in a shinsa, so they can provide better quality. Is this working? I'll leave that one open as bait
"Apparently" isn't the way to go here - you will need to come up with the name of that publication before it can be considered.
Shigeo (again NBTHK main office) says in his writings about Owari sukashi tsuba
"Let's start with Akiyama and Ogura. We know that some of their theories have been disproven but that does not lessen their contributions"
I think we can also include Haynes in that list. Although his theories don't always hold up any more, his contribution was great and shouldn't be overlooked.
He was a student of Torigoye, who had a repution of being strong on iron tsuba (not so much on kinko tsuba)
Regarding YKB - I suggest you read the "Owari to Mikawa no Tanko" - published 1982 so well after Akiyama and currently considered the most in depth work on the subject. Again, they go deep into the history of why YKB is indeed Owari based. Are there points of discussion in this book as well? Yes, any good thought provoking book will leave some open endings.