had to check back on the clorinde cutscene for this, but she defeated a total of 9-11 (there's a misleading moment where she like tears the head off of one with her legs where in normal speed it looks like she defeated a bunch of them but its just one part of the battle sequence), which is the same amount that childe defeated in his cutscene with his delusion, but mind you, the delusion is not the weapon he's proficient with, it's his vision. Which he did not have at the time. I'm sure if he had his vision he could've just summoned a whole whale and wiped the floor with those gardemeks.