What does a mound accomplish? If I were to change the green to avoid the two step hazard, I would just push the green edge to the water and have a constant bank.
There may be some reasons for pushing the green back. At Cowboys, our third green was going to be right on the water, but someone decided a sewer line had to go through right there, so we moved it back. While we didn't use a bunker, its far enough back that some might consider tying water together with green visually.
Personally, I would have more tendency to have the save bunker along the water on early holes in the round, when on the slice side and on longer holes, and push the water right to the green edge on shorter approaches, and later holes. As always, thats just a general rule.