I've done it both ways and neither one is easier then the other. There is plenty that can go wrong with the "cheese" method, and thus can take as long or longer to complete. People will defend the way they did it because it's not easy. And people who did it the "right" way want to feel like a special snowflake so they will cry cheese. Fact is, we decided as a community that killing the ogres and stacking up in the middle then running out to the bombs, was the way it was meant to be done. But the raid came with no instructions outside of defeat Oryx, so however your method is your own legit strategy.