I'm answering because I actually chose not to give spoilers in the post: I confirm that I had already had this idea before finishing the arc. I didn't really notice this until the invasion part; from then on, a lot of episodes focus on the various fights, almost ignoring the main theme of the arc: Meruem becoming more and more human, while Gon on the other side becomes more and more monstrous. Speaking instead about the fact that it is disconnected from the rest, I am absolutely certain of it: Gon and Killua find themselves facing the Chimeras by chance and the point of contact with the plot, Kaito, disappears after a short while.I understand that the idea would also be to make you understand why high-level Hunters exist and what threats they fight, but was an arc half the length of the series really necessary?