I am getting worried with the drop rate on Gruntt. I've gotten close to the end of the chapter and no girl has dropped. This accounts to about 500+ battles I would guess, by the scores I've had in contests I've come to this estimate. I have level 45 and 15 girls.
With the Dark Lord and the Ninja guy I've gotten all girls before finishing their chapters. I want to know if this is normal, just to check, to know where I stand with the luck.