Large maps in Destiny are an extreme rarity, not to mention a few of them were removed from the current playlist to be abandoned in the classic playlists, and even then never appear in the 1st place. We need Combined Arms for those maps, not only since sniping will actually be understandable and easily countered by other snipers because of the extreme lines of sight, but because the maps were actually enjoyable and not just Call of Duty.
Edit: Shoutout to Orange N Blue 7 for thinking up the idea of 12v12 Combined Arms. Definitely would be a fantastic idea.