The Bowline and the Sheetbend are not the same knot. I have a training video somewhere illustrating this, I will find it and post it to YouTube for us to discuss. They look the same, but they are not the same, if you tie a Sheetbend and use it as you would a Bowline it will fail!
I will look with interest at the video.
I accept that if you use a Sheetbend as a Bowline the pull is through different parts of the knot so it may not be as strong. I would be interested if the video shows a comparison of both knots on the same rated rope/cord and pull.