Spoken from a true fan who doesn't know much about football.
Anybody who has ever played in the trenches will tell you it aint about how big or fat you are (looking at you, James Carmon), it's all about leverage and footwork. As a matter of fact, being big can put you at a disadvantage. James is overweight, slow with his feet, and would get burned by any DE in this league.
For more on size, just ask JC Brignone, who is without a doubt the best center we've had this decade who is every bit of 6'1".