A wedding that has 150-200 guests is considered big. That many runners is a small race. Races that have less than 300 competitors is considered small. In other words, if you are the director of a race with 300 or more runners and walkers you have to plan for a pretty big event. At weddings, they have caterers who will make sure there is enough food.
Races have their post-race refreshments.
Let's talk entertainment. Nowadays every big race has to have an announcer to keep things going smoothly. No, an announcer at a race is not necessary. Then again, I have been to many small weddings that didn't need entertainment. Some weddings want to have little party gifts for the guests.