What you are asking could possibly be done but not quite as you describe.
Using the StreamPublisher, in your streamschedule.smil you would have a stream tag and a playlist tag for each stream in the group. each playlist would have the video tag set to one of the renditions.
You would then have a separate smil file that is used for playback. This would reference each of the live streams that are created from the publisher.
One issue you may have is that there is nothing in the StreamPublisher to ensure synchronisation between each of the streams so over a period of time, they may drift out of sync far enough that switching would fail to work.