‘Mexodus’ Review: The Underground Railroad Runs South to Mexico in a Pasadena Playhouse Musical That Feels as Spirited as a Two-Man ‘Hamilton’

To paraphrase Aaliyah: Cast size ain’t nothing but a number. In the realm of the theater, no one exactly equates the number of headshots on a Playbill page with the ultimate fulfillment a stage show provides. Still, a question may arise: How few people can you have in a musical and still generate just as…