lol some guys are complaining that they have too many girls to keep up the upgrades and some are complaining that the girls are not dropping from the bosses and the drop rate should go up.
slowing down the frequency of events and decreasing drop rate would worsen the playing experience since getting girls is part of game progress. so less girl drop mean less feeling of "accomplishment" from playing the game.
better alternative would be to decrease the cost of girl upgrades