‘What would the landscape of superhero comics look like if there were no sidekicks — or their felonious equivalents, henchpersons?” asks author Jon Morris in the introduction to his very entertaining book “The League of Regrettable Sidekicks.” His answer to this question may surprise you (or not, depending on your interest in comic book superheroes): he says the landscape would look “roughly the same.” Aww, poor sidekicks and nefarious minions. Of course, some superhero partnerships are so famous that imagining the superhero flying solo (both figuratively and literally) just doesn’t compute.