One idea that would murmur complaints about drop rates (but not silence, of course, that wouldn't be reasonable) would be to increase the girl drop rate, but allow for duplicates to drop. If a girl the player already possesses drops, she gets a free affection level upgrade, and if her affection is max, the player gets her contribution cash (per hour or per click) up front. This would make it easier to get at least one girl from any opponent, but would still require persistence and luck to get them all, though a player who tries can get an occasional windfall from attempting it.