>>58753568They always specialized in something very relevant to the current game
Elm - breeding (Literally the big new thing at the time of Gen 2, on top of baby Pokemon)
Birch - habitats (Gen 3 gives more of a focus on the locations Pokemon show up in, however FRLG's dex is actually the one that list Pokemon via their habitats)
Rowan - evolution (new evolutions for older Pokemon)
Juniper - origins of Pokemon (like
>>58753606 this anon said, Gen 5 was originally planned as a reboot)
Sycamore - mega evolution (Obviously because of the new gimmick, but Sycamore also says he used to study under Rowan)
Kukui - moves (z-moves)
Magnolia - dynamax
Sada and Turo - terastallization
Oak is the only one that doesn't seem to specialize in anything, he's just an in general Pokemon Professor, and seems to be the most successful one, but he was also the first we were introduced to, so a given
