>>283637310
Because for me it was basically impossible to create a 3x3 without imposing such rules for the mere sake of eliminating excess candidates. To even approach a possible 3x3, from over a square dozen options, I had to say:
>No two battle shonen girls
>No two isekai girls
>No two generic art style girls
>No two girls from the same IP
>No unfamiliar girls
When expanding to a 5x5 (see >>283627815 ), I dropped the first three rules (even though, ironically, I never added a second isekai girl), but made sure to keep things balanced across both themes and eras. Either way, I can't imagine being asked "Which 9 or 25 anime girls are most representative of your taste in women?" and just oversaturating it with one or the other thing, instead of formulating a thoughtful answer, with how spoiled for choices we are.