It's not a useful argument anyway. It's like arguing about what's the best sexual position: what you and your partner can agree on means infinitely more than what a bunch of total strangers on Hacker News think anyway.
This isn't some search for objective truth. It's me sharing my opinions and the supporting rationale in the hopes that somebody might find them useful when they run into this situation in the future.
And I'm just saying the opinions of people not personally involved in these kinds of equity decisions are of limited value, and that our discussion has easily reached that limit.