Dogen says that he speaks Japanese to help keep a metaphoric distance between him and his people, to make the situation easier when they don't like his decisions. This might mean that there are two groups of others working somewhat independently, one a group of nomads previously led by Benjamin Linus, John Locke, and Charles Widmore, and another based in the temple led by Dogen and whoever preceded him. If this is the case, the only logical reason for these two "squads" of others is that they would have different objectives and tasks.