This. The later you come into a given project, the less equity you would be justifiably entitled to.
As to the original question, if you are starting from zero and you want a means of avoiding critical shareholder deadlocks, you can split 45/45/10 with the smaller portion going to a party both founders agree will be impartial. This person can be the initial angel, or perhaps a minor founder who accepts a smaller chunk in order to maintain his dayjob.
You can also maintain 50/50 splits of ownership but still break executive deadlocks via a third vote by mandating a third seat on the board. This won't help fundamental shareholder deadlocking, but disagreements rarely go to the shareholder vote level.
As to the original question, if you are starting from zero and you want a means of avoiding critical shareholder deadlocks, you can split 45/45/10 with the smaller portion going to a party both founders agree will be impartial. This person can be the initial angel, or perhaps a minor founder who accepts a smaller chunk in order to maintain his dayjob.
You can also maintain 50/50 splits of ownership but still break executive deadlocks via a third vote by mandating a third seat on the board. This won't help fundamental shareholder deadlocking, but disagreements rarely go to the shareholder vote level.