The ideal situation seems to be that anyone doing work immediately vests ownership upon performing the work.
Granting stock (not options) with no vesting schedule is probably one of my biggest regrets.
To add counterpoint to the discussion, Mark Suster (VC Upfront Ventures) uses the factors you listed as reasons for not doing equal split.[1]
Robin Chase (co-founder of Zipcar) also regretted her decision to split equity as 50/50.[2]
I'm not arguing with you. Just pointing out that reasonable people disagree on equal/unequal philosophy using the same reasons as justification.
[1] https://www.youtube.com/watch?v=oAHgGUFjK3c
(A slight correction to the video about Youtube's 3 cofounders: I believe the Youtube split wasn't equal as 33/33/33; instead it was 45/45/10.)
[2] https://hbr.org/2016/02/the-very-first-mistake-most-startup-...
Majority of people starting a new company are very unfamiliar with equity splitting, vesting and everything related to theses things. On top of that, usually the team members aren't even well defined yet, same as the idea for the company.
A lot will change even in the first 6 months of a company that would justify different equity splits for different members that are still founders but join with different (implicit) roles and at different times.
Sadly, unless the founders are extremely lucky, it will probably take them a lot of experience and maybe going through failing a few times until they get the equity split right from the get go for a new company.
And there's a bunch of other external and unpredictable factors. For example: about 4 years ago I started a company with a couple other people - each founder joined at different times and had different amounts of equity - a few months after winning a hackathon, incorporating the company, raising some angel money and getting our first few clients, we applied to YC, got an interview and then got an offer to join YC, but one of their partners wanted us to change the cap table to remove some of the people that had equity and re-split the equity among a subgroup of the founders. We couldn't do it, so they withdrew the offer to join.
Typically during the initial phase (and forever forward) visible contribution changes.
Do you think it is a coincidence that the leader of Alphabet resigned not long after failing to answer one of Google's own interview questions about how he might split up pirate booty?
IF you are starting a company with others, decide week 1 what the split of equity is and who (of any persons included) are cofounders or part of the "founding team".
IF you are starting a company with other cofounders, week 1 split the equity evenly and assign functional roles (not necessarily titles - those can evolve).
I have seen multiple companies explode, friendships deteriorate, businesses die a slow death, or waste hundreds of hours (and dollars) working through the emotional debt built up from not splitting equity evenly.
- Edit - changed day 1 to week 1 because typically there is a process of "should we start a company", "should we do it together", then "how" that takes some time. But once the "we are going to do this phase starts, you're in week 1