Wow. That is going to be an interesting adventure you three are taking on. Certainly, I hope that the bride and groom understand that there will be three shooters. Hopefully, you guys will have designated each shooter for a specific function well in advance of the big day.
Find out how many guests there will be and the sequence of events that are planned. Personally, I would have one main photographer be responsible for all the formal shots. One person can be the "second" shooter getting the "behind the scenes" shots, shooting in an editorial style. The third can be a rover shooting whatever looks interesting.
I used to enjoy shooting as 2nd with black and white film in the editorial style. No formals and no restrictions. Get them in hair and make-up as well as getting dressed, etc.
Good luck and have fun!