While the halberd's blade offers a lot of options for hooking your opponent, it equally gives them an opportunity to hook your polearm and manipulate it themselves. The simpler spearhead is also lighter than that of a halberd, allowing for more sustain when fighting for long periods.
I would definitely prefer a halberd (or billhook) over a spear given the choice, but it's not as much of a direct upgrade as you might think.
This is a great idea! Doing it on Google Sheets is fine as a resource for this community, but it wouldn't really have discoverability outside of it if that's where you want to go with it.
(Also it's spelled Wisconsin btw)