And now you get into the issue that someone might end up with 50% equity and stop working - so then any and all work the other person does benefits the other on

And now you get into the issue that someone might end up with 50% equity and stop working - so then any and all work the other person does benefits the other one. :) This is why I'm not a big fan of offering large amounts of equity to people that you don't know and haven't worked with before - so you know their value, and how well you get along.