I didn't saw anywhere with which criteria the father selected them... personally, I clarify that this are my opinions and I don't really have proves that confirm this, I think that they are chosen for this reasons:
- two of them seems the big sister type but one seems a love oriented that warm your heart while the other seems more "onee-chan will teach you some nice things" (they are the tallest ones), probably chosen for grant him some love since he seems he need it.
- a pair of twins (left), one reserved in kimono and the other seems more open and modern, probably they are the loyal type that will not betray him with the not in kimono twins being a little a tsundere.
- a gal and bright like one (the dark skinned one), maybe for push him becoming a more social person thanks to her influence
- a seems like shy one (the girl on the right of the gal), probably so that they make a connection more similar to a person and its pet... no, I don't mean the dirty one.
- the girl-next-door or childhood friend type (in the center), a standard type of choise
- maybe a model like one (the black haired girl on the left of the one in the center), really dunno about her
- the AV actress (from the poster in his room probably she was a singer idol that decided to become an AV actress but dunno about it), probably chosen because he like her and can lead him in the bed giving immediately an heir but still it seems a little strange as choice since normally we see japanese guys more interested on "pure and virgin girls"... never understood that.
- the dark one (the one in black in the right), probably is someone that distance herself from people so she is there basically only for bear a child and nothing else, leaving him to have all the lovers he desire
and i think that his childhood friend is a gold digger she have borrowed 20 mio from him and then she was gone but why his father bring such a girl in his life again that i dont understand