One of the things I know the developer doesn’t like doing is overriding default WP behaviors. I think he’s said in the past that it falls outside of what he wants ACF to do. I found some information about how this can be done, have not tried it though http://wordpress.stackexchange.com/questions/2474/disable-dragging-of-meta-boxes
I guess I haven’t run into this problem because I rarely put groups above the content editor and when I do it is almost always because I’m going to disable the content editor. I generally set groups like page banners to a higher order and let them appear below the editor.
I can mark this topic for the developer to take a look at if he has time
