Personally, I would count any electives they did in the summer as Wolf electives, not Tiger. The more Wolf electives they do, the more arrow points they earn. They get to wear the arrow points on their uniform until they move on to Boy Scouts or get the tan shirt as a Webelos II. The Tiger electives just earn you the yellow disks, which aren't worn on the uniform at any time after being a Tiger. There's nothing wrong with rewarding the boys who put their time in as Tigers and let them start on their Wolf electives, rather than holding them back because new boys will join in the fall.