Trust me, I know it is. As I said above with CCH2, at least four of the Elemental Genres could apply.
But I think it’s reeeeeeeally helpful to narrow it down as much as humanly possible so that we, as authors, fully understand what we are trying to accomplish with our stories.
Because if we don’t truly understand, no one else will.
And even though not a word of CCH3 has been written, I already know it is Ensemble/Drama because the MC finally “grows up” and becomes a threat and can help the MC’s classmates tip the balance of powers between all the factions just a little bit. That is the focus of the story. The MC’s growth and the MC’s classmates. Just because I don’t mention Humor, or Relationship, or Thriller doesn’t mean there won’t be any of that…it just means I’ve decided on the main focus.
EDITED TO ADD: And so when I’m writing CCH3, if I lose my focus along the way, and get off on too many tangents, I can always regather myself and think, “Back to Ensemble and Drama.”