I was brought into the trade to look for the light in a setting, unload and refill cameras, haul the gear, and watch for 'the' moments. The emotion in the moment was the link from the mechanics of the art to the emotional memories of "the shot!" We had to capture the technical print while the emotion was at the peak. Yeah, I'm an old romantic, but; your photographer is driven by their years of training and their passion. What motivates them? Ask about their insurance--but also their goal in capturing your wedding. Check on their licensing--but also the feelings you get from their images.
Remember, anyone can point a camera and click. You want a professional that knows when.