kaneki isnt the one eyed king.as exiting as it is in all mangas the protagonist to become the most strong the ultimate macho,the king(which by the way kaneki is nothing of those 3)this isnt the case.
eto formed aoogiri tree 14 years ago.she knew the ccg and V connection from her mother diaries.she knew that a one eyed ghoul(like herself) is the mark of change.she made aoogiri in order to gain more muscle,troops to fight with.the story of the OEK that runs aoogiri was there before kaneki became a ghoul by accident 5 years ago.her goal was similar with kanou and they work together.both kanou and eto wanted rize as a donor.now they use yoshimura
she is making one eyed ghouls because they mean power.they are upgratable soldiers.the last 6 months kanou with the corpses of gagi/guge/shiraru has propably build dozens of seidous brothers and sisters.
the one eyed king is someone else.if he exists at all and isnt an icon a messiah story from the 100 old OEG that appeard before then the king is someone we have already met but we dont know that he is a oneeyed.
or he is a messiah storie and eto is looking for canditates.
but kaneki isnt the OEK. a possible choise for eto maybe.but the real deal....no.
he became a ghoul before 5 years.and the sasaki persona was more or less 3 years.so the ghoul kaneki is only around for 2-2,5 years.nomore.
he cant take the role as a king.hes just a victim of shitty luck in reading a womans mood.and souta being there that moment.or hide/souta.nah hide isnt souta.but its a miracle that in all those tunnels filled with ghouls running for their lives in V14 he wasnt hurt at all and was able to find kaneki.he propably had a gps transmitor put on kaneki to find the right tunnell.and was able to hide real well so all the tunnells filled with ghouls running to arimas ixa werent able to smell that snack(hide).
but thats another storie.