A lot of good discussion around the Arrow of Light here. As a former Cub Scout, Webelos I and II leader, I was fortunate to have 100% of my boys earn Super 20 and transition to Boy Scouts. They found themselves well ahead of the pack, so to speak, of other boys transitioning from other Packs. Not that they were any better than the other boys. They simply impressed their new Troop by demonstrating mastery of the concepts, flying through Scout and Tenderfoot ranks in little time, taking on leadership roles, and helping other boys in their new patrols. They added value very quickly and their parents pitched in to help the Troop.
Two keys, in my opinion, were parent / family involvement and a focus on what really matters during the Cub and Webelos years. We made a big deal out of our Arrow of Light ceremony and reached out to the parents to bring them onboard - well before the event.
I made this video to explain the ceremony and the patch to parents and participants in the ceremony. Feel free to use it if it helps your Pack during transition:
http://rch.evsuite.com/arrow-of-light-significance/
Here's the YouTube version (open for embedding):