I think the only thing in Vanguard that had shards was the Ancient Port Warehouse raid dungeon. Shards weren't true instancing since they were still all open world, but it served sort of the same purpose. APW had 6 shards, and which one you entered was determined by a selection box when you clicked the door to zone in. Each shard was a physical copy of the dungeon, and anyone could enter any shard at any time regardless of who else was in it.
So it was all open world raiding, but they made 6 copies of the dungeon because a) even though you could theoretically have 3-4 raids going simultaneously content wise, the performance didnt actually allow that, and b) raid content was late in coming and as such the game was top heavy and there were plenty of guilds ready to jump on APW raiding on day 1.
