Pony-boy never calls Johnny a 'follower' in the book, although he does describe him as "the gang's pet, everyone's kid brother" (12). Johnny does seem like he might could have 'follower' characteristics, but when Dally gave Cherry a hard time at the Drive-In, Johnny tells him to "leave her alone" (24). Pony-boy is more than a little surprised that Johnny would stand up one of the toughest members of the gang, reflecting that usually "Johnny couldn't say 'Boo' to a goose" (24). A boy who had a 'follower' mentality would have gone along with Dally's crude jokes.
Johnny's diminuitive personality seems more of a product of his abusive home life than his personal character. When Johnny is beaten up badly by the Socs, Pony-boy remembers that "he had never been a coward" and "he stuck up for the gang" (34). He stays with the gang for moral support; they are more like family to him than his real family.