It might be because you have to get hint art from other kingdoms before you can get the last few moons in that kingdom
hint arts, visitants events, dressing... they have calculate everything in an order, even just because of moons ruting is maybe faster a travel more by a painting
Some moons require actions to be taken in other kingdoms to appear/become obtainable. These include hint art moons, outfit moons (especially the Style Sisters in Lake Kingdom, because you need a Sand Kingdom outfit and a Moon Kingdom outfit for a couple of them) and especially the Tourist moons (you talk to him in Sand before he appears in the next kingdom on his route, etc.). There are also seed moons that take approx. 20 minutes to grow, so the route is that you plant those in the first or second visit, allow them to grow and then get the moons in the next visit. As well as considering the route warp paintings take, all those factors (and probably more that I'm forgetting) make it so that it's faster to revisit some kingdoms multiple times.
