Agree, you need 3 references (none of mine were ever contacted), not LORs. Rumor in the forums is that as little as one internal rec will get your application reviewed (ie, pulled from the stack and actually looked at by human eyes). After that, it's up to how your app scores as to when/if the invite comes.

I had 2 internal/5 external LORs and used them to validate my credentials, meaning I used someone from every assignment/phase of my career (retiring AF) to show that I not only have my blocks filled but I've been a "good dude" that people liked flying with. Threw in some community service stuff, too. March hire, FWIW.