Paul, I don't think you should have to move your subforms at all - if they're in a flowed container, then the ones that you want should show up at the top, and the ones you don't want shouldn't show up. You need to use the correct Presence setting (Hidden) to make sure that the hidden subforms don't take up space on the page. (if they're "invisible" they still take up space in the layout).
Hope that helps,
Mike