I used to main bows just because melee weapons couldn't reliably kill all parts, especially higher ones. But with united destroyer that doesn't matter anymore, so I went from rifle to naginata for everything but those hyperactive bosses.Not feeling the Club (meh) or the Naginata though... well the latter seems cool but I kinda worry about not being able to hit parts that are high with it.
Great thing about the naginata is that at max hyperskilled you're hitting everything around you, so building the united gauge goes real fast with a team of fast melee. Hayatori + Reki + anyone else fills the bar pretty much every 2min.