Why did Namikaze Minato seal Kyubi no Youko with ghouls?

Naruto met his mother when he contacted him. His mother recalled that when Naruto was born, Watergate and Haixinai were next to Naruto. Because Watergate is a great father, in order to let Naruto see his mother when he grows up, it is the strongest deity among Naruto at present. If Kyubi no Youko's power is not completely sealed, Naruto's body is Watergate, so it can only be sealed with ghosts. Watergate thinks that Naruto can make good use of chakra in Kyubi no Youko and chakra in Kyubi no Youko. These two chakra are almost infinite, so ordinary seals can't work. The ghost seal can only seal half, leaving the other half in his son's body, hoping to help Naruto in the future.