I'm not sure it loads all the players of view only leagues.
I've got all the nations loaded in my game (and some), and I've set all to view only (mostly just top leagues loaded) and only have some european nations as playable and as I turned the nations to view only the player count in the database went down (helped stability a lot)
View only is useful for having other nations actually play and allow them to really grow and produce better regens IMO. If you have no desire to coach in Denmark (or who have you), but want to have them loaded, set them to view only.