TV Negan is of average built but the comic guy was all muscle.

Being a leader has nothing to do with size. David Koresh, Jim Jones, Fidel Castro, Hitler etc etc weren't physically built men, yet they were followed and worshipped. You protect someone, feed them, and provide shelter in the ZA it doesn't take a lot of persuasion to get them to follow or bend to your will. Negan operates on fear.

 

Negan secretly has a small you know what, therefore that is why he acts the way he acts. Like a &*%&@*(^@(

 

Negan wields the most powerful force in his universe -- the walking dead writing staff.

 

He uses the dark side of the force.

 

My take is Negan led a small group and had a Shane like attitude (little bit smarter) right from the start, but there was no Rick to stop him from convincing everyone to survive at all cost snaptube vidmate word to pdf and kill other people. From then on when he started to get high on power and his group grew in numbers he got the idea to run a protection racket on other communities to thrive.