Once you see a hen swallow a mouse whole, you realize the size of the food doesn't matter to the birds. If there's too much food on the floor, they don't get fresh rations until they clean it up. It's easier for me to see pellets on the floor than crumbles.
Crumble vs Pellets - Page 3
There is generally less waste with pellets than with crumbles. Once birds reach maturity, size of the feed does not matter. We have done some studies at our Gray Summit farm using large chickens and bantams, and there was no difference in intake between pellets and curmbles, even among the bantams. Your analogy regarding eating a mouse is a good one!