If one will be able to play all the selections, then certainly finish with the most polished one.
I wonder, as I must, what would happen if teachers in Britain didn’t use any ABRSM material at all and freely chose repertoire on their own. Would there students be unable to be admitted to school, however good?
I ask, because in the U.S., we have no required repertoire except for competitions or auditions, so we have complete freedom to choose repertoire.