Photographer question

Okay this is driving me nuts...I found a photographer i loved...but FMIL said that because we are having over 200 guests, we need two photographers...however, the photographer told me that a second photographer is for candids, and because they use digital, no one is needed for lighting.

Do I really need the expense of a second photographer? I don't think it is necessary...but this is all FMIL talks about...grr