They could take and hold certain places, like the place where you find rasputin could be patrolled by vanguard npcs and every once in a while you can join a public event like," Help the Vanguard defend the skywatch against the Fallen attack force" or "Lead the Vanguard to retake the skywatch" certainly would add something new to patrol and spice things up a bit, on the moon you could have the vanguard defend archers line and dead orbit could defend the temple of crota or the archive ect, it could give factions a bigger role in the story, imagine patrol missions for faction reputation regardless if you wear a faction bond/cape. Help me get these ideas to bungie guys !