I just checked the fishing tables in Gen II and yeah it seems to be mostly Gen 1 Fish, with the only Gen 2 being Corsula, Remoraid, and the Chinchou Line and with those 4 you kinda need to be picky.
Idk what is currently in the fishing mini game but an idea rather then have the MC fuck a Remoraid, fishing one brings a Mantine over. I think someone else has pitched this before but that's probably worthwhile.