Why do many critics believe that Hellena is the Rover rather than Wilmore?

Broadly speaking, there are two reasons why critics might think that Hellena is the rover who gives the play its title. The first is internal to the play: Hellena roves more widely from her assigned course than anyone else. Wilmore takes few social risks with his actions and attitudes; Hellena risks much. The second is historical/biographical; Hellena makes independent choices somewhat similar to Behn's own, and so one might think that Behn might make such a character the namesake of the play.