Everyone has to put their 2 cents in

Ok, so the most stressful thing about planning this wedding has been listening to everyone's criticism. As of right now, we have our church booked for 3:00 and our cocktail hour starts at 7. In my mind it's fine because we need time for the receiving line after the church, pictures at the church, traveling from church to RH (there will no doubt be traffic from Queens to LI on a Friday afternoon in the summer) and then taking our pictures at the RH before the CH so FH and I can be at the CH. My grandmothers have been on my a** about having too much time in between the church and CH. They're worried about what everyone's going to do in between. I told them that I can't worry about what 50 people are going to be doing for 3 hours, we have to do it this way because it works better for us. Am I wrong? I feel like not many people will come to the church anyway (only immediate family and close friends). My grandmothers have been giving me so much grief about this that I don't even want to talk about the wedding with them because they ALWAYS say something! So frustrating!