For my personal approach to photography, which is quite documentary, I tend to work alone and blend in with the guests. However, having two photographers really does depend on the number of guests and location. For a small intimate wedding with everything in one location, two photographers can be overwhelming, but they can be beneficial for larger weddings or those that take place across multiple locations. Having two photographers means one can be with the bride and one with the groom for the morning preparations. During the ceremony, you will have coverage from two angles, usually one from the back of the ceremony room and one at the front. This can give a great view of both the bride and groom's reaction when they first see each other at the aisle. It's also great for the ring exchange and first kiss. During the reception one photographer can focus on the family and group pictures, whilst the other can take relaxed guest photos. Similarly, during the speeches, the room can be split between the two photographers to try to capture all of the guests' reactions. Have a chat with your photographer, and they will be able to help guide you on what would work best for your big day.