I've played every Pokemon game since the beginning of time and watched every episode of the show and seen every movie. My brother and I used to draw Pokemon on index cards and throw them in our yard and "fight" them when we "accidentally" stepped on them.
Pokemon Red/Blue VS Pokemon Sun/Moon honestly sun and moon wasn't that hard for me. I beat it with in a few days, and never found any issues with beating the composition. But maybe that was just me. (And no I did not transfer my old pokemon to the new game, you can't until January 12th)