Thank you both for your input!
@zorloth Wierd about the doc. Does this link work? TCG in Figures - Google Sheets
My approach was to generally overestimate! Which perhaps lead to an idea that theme decks and non-main sets be excluded. I’m not quite sure how to handle decks but I could add larger non-mains to the timeline to reduce the averages!
Your insight on ex era pull rates over all and the quirks / nuances have been extremely helpful and sited!
Good thing about box toppers is we can figure those out pretty easily with the info and formula already in use!
Point 2: noted! is this type of error prevalent throughout?
Three makes a lot of sense as to why they’d be the same pull rates! If the ratio for theme decks is basically ⅓ and pull is /6, could we average holo rares in Ruby to /4.5 overall?
Please feel free to share more, it’s appreciated 
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@bk2021 yes sheet rarity is totally a factor that should be considered! I’ve read through this thread https://www.elitefourum.com/t/the-english-pokemon-card-rarity-guide/39762 a bunch but don’t fully grasp the math or tables.
From what I can tell, a lot of the authors conclusions about sheet rarity and pull rates align pretty well with other sources (especially for later sets). Understanding this better may help with what is missing like Alt Tag Teams, the categories you mentioned and others!
Can someone ELI5?
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You both remind me of a major question of this project: can a confident margin of error actually be achieved?
Anyway, thanks again! Will try and update this more. There’s certainly a lot that can be ironed out.