lol
I'm afraid the two counteract each other and cancel out. Boyish charm is kind of an innocent, cute charm. Kind of like what you might associate with Michael Cera.
Roguish charm is kind of a devil-may-care, cheeky bastard kind of thing mixed with maturity and sex appeal. Kind of like what you might associate with Johnny Depp or possibly Brad Pitt or George Clooney (depending on which movie they're in).