It is known that generally muscle units are recruited from small to large, and that typically also means slow to fast twitch. This principle is called Hennman's size principle.
I've seen many articles backing this claim up. However, I'm curious if there are any known situations where this principle is known to fail. (Perhaps when there is a known impulse arriving shortly and it needs to be opposed by large fast-twitch muscle).
All I have found so far are articles which agree with the principle, but it seems surprisingly simple for a biological system.