Three rookie wedding shooters all at the same wedding ? That sounds like some sort of made for TV comedy. I predict that things will either go very smoothly, or it will be like the three stooges ! I hope it goes well.
I also hope that the wedding party and families are very down to earth and not like many that I have worked with who wanted the lowest profile photographers with the highest quality results.
You'll undoubtedly get lots of images to work with.
As far as equipment goes... KISS you have two back up shooters, so if you can coordinate what type of shots each will be getting, you won't have to move around a lot, or change lenses much. Extra batteries are a must.
Also keep in mind that if your "friends" aren't experienced wedding shooters they may get distracted by the festivities and not get the shots you need. i.e. alcohol, women, dinner, cake. If it is a long wedding/reception day, they may tire and leave all alone.
Attending a long wedding/reception and shooting one are two completely different experiences. Not for the faint of heart, or FEET !
