I am amazed at how differently one raid group will tackle a boss compared to another. I usually try to run with people I have raided with before, and most of the time with raid leaders I have run with before. This leads to me getting very used to doing things a particular way, but I do understand some fights have different ways to do things. Yet there are other fights when one way is used because it is simply better and I believe the 4-horsemen encounter is such a fight.
I am not going to explain the whole fight here, but the key is that each boss emits an aura that will but a debuff on any players in range. Each time the debuff is applied, damage is taken by the player, and increasing with each count. To avoid this, the idea is to move away from the aura and let it completely fade; or move the NPC away 🙂
Moving the front NPC s back and forth in the front rather than the players is the way we do this, when we are not just burning them down. We do this so to reduce the chances that anyone other than a tank gets a 4th stack.  What happens is at three stacks, the tanks start running to the middle with the bossed in tow and everyone else back up just a bit into their corner.  At the middle , or near it, the tanks taunt the opposite boss and drag them back to the corner the tank started in. Yes, this does require a bit of work by the tanks to time the swaps and will probably take some practice but it makes the fight so much cleaner.
In fact it works so well and is the way I have done it with every other raid I have faced them with, that I did not even consider having players swap as an option.  To me there there area only two ways to do the fight; boss swap or boss burn.  That is until tonight when I wiped a raid I tagged along with, when they swapped players.
When the switch happened I was very confused standing in my corner and getting a 4th and 5th stack, and having my tank out of range.  Note, I did not make that mistake the second time, and we passed the encounter. It was still more messy than I would have preferred *shrug* but its not my regular raid, so I made no comments for now.  Though I think I will chat with that raid leader tomorrow and explain why my regular group, and everyone else I know, does it different.
In the end that fight simply re-iterated to me that some people will work out tactics that are completely different from how I would do it.