HxH does not always adhere to a strict arcstructure.
It did so mostly for the earlier parts, but at least since the Chimera ant arc, it mixes big subplots that could be their own arc into other arcs.
Just take yorkshin. We had the plot of Gon and Kill trying to aquire GI, so it basically could have been a prelude to the GI arc (learning how to make money, learning how to get into battera's team, so on), but Kurapika's Spider arc was just as prominent and both of these two narratives mixed occasionally.
Noticeably, Yorknew does not begin nor end with Kurapika's story. It begins with Gon's search for GI (kill and gon being at whale island) and ends with them entering the game. The whole spider subplot is a big arc squeezed in between the 'entering GI' arc.
However, at least since yorkshin, you usually have several things that could be their own arcs going on at the same time.
Gon and Kill training for Netero's expedition or hanging out with Kite's group could be their own mini arcs length wise and didn't yet have a lot to do with the King.
For the election arc, we once again have two narratives which intersect in keypoints (alluka and election), but still both could be their own arcs mixed into one another.
The DC arc is the most complex arc yet. We will probably see more than one arclevel plot embedded into it.
