So the Flight 815 group once again meets a group of people who know a lot more about the island and what's going on than THEY do. With all the people on the island(s), why haven't they been tripping over each other before now?
The people at the temple and The Others are the same people.
Ben sent them all to the temple to hide out, back at the end of season three when he and Alex went across the island to cut off Jack and the 815 survivors and to try and get Jack to not call for help on the radio phone.
At that time Locke was with the Others and he saw Cindy there as well. Ben tells Richard to take the Others to the Temple to meet up with the rest of "their people" since they would be safe there.
Richard did that (off screen) then he left the temple with a small group of Others and went looking for Ben and to see what was going on. Richard's group then met up with Kate & Sayid and worked with them to free Ben from Widmore's merc's (end of season 4).
So, the Other's in the village, and on Hydra island, and at the Temple are all the same group of people, just spread out over the island in different areas. The Temple, though, appears to be the main HQ and the one area where they feel "safe". At least Ben said it was the only safe place on the island (when he was trying to get Alex and her mother to get to safety).
I would guess that the Temple is the traditional Other's HQ and base, and it was only after Ben took over and Dharma was wiped out, that the Other's started living in the village and doing scientific research and recruiting scientists (like Juliet) from off the island to come work for them. It was probably Ben's decision to do all of this and it might have been the reason for his people to lose faith in him and a reason why he eventually got cancer and the island didn't heal him.
he was taking things to far away from the islands natural order of things. Or maybe to far away from jacob's plan.