I don't think the trilogies need to really connect. No real need for a vast saga. Each trilogy should have been pretty much self-contained with characters from the last introducing the next.
Were it up to me, the PT wouldn't have been about the fall of Anakin. He and Obi-wan would have been in them but wouldn't necessarily be the stars. It also definitely would have ended before Vader.
I like the idea of a 30 year gap between each set of trilogies.