I think it depends on how long your gap will be between the ceremony and breakfast? Sorry if I missed it? If it's an hour or so I'm not sure you need anything additional. People expect to spend some time chatting etc, I for one am always glad to have a drink and something light to eat, but wouldn't be bothered about entertainment as I'd be chatting to my friends and family.
We went to a wedding last year where the gap was 2 and a half hours, they served pimms but no canapés. It was a bit too long really, it was quite chilly, we were hanging around outside and we were all fairly hungry. I think you need to judge it based on your situation.