Seems a bit counter-intuitive, no? Jiu jitsu is pretty much centered on the premise of what one would realistically do during a fight (for the most part- if someone did the worm guard in a back alley street fight I would both annoyed and just a little bit impressed).
Exaggeration of movement in a technique does have its place, in some situations. I remember one of our old instructors explaining this concept to us: in live training and in competition it is tremendously rare to fully, perfectly execute a technique, such as a sweep. So, by training the body to “learn” that muscle memory of exaggeration, you are priming yourself to be more successful in a technique in a live situation, rather than minimizing your movement and then wondering why that sweep/etc. never works when you are rolling or competing.
I’m certainly not saying to do this for every technique, but in some cases, particularly techniques that require a big movement on your part, it’s better to go big.
Have a great day everyone!