The Oklahoma Sooners have been an offensive line pipeline into the NFL throughout their history. You could make a case that the Sooners boast the two top tackles in the NFL between Trent Williams and Lane Johnson. Johnson is the lynchpin of the entire Eagles' offense and is the best pass protector in the NFL right now across all positions.
For all its new rules and increase in penalties, the NFL is still a physical, violent league. Being an elite athlete, particularly one with size and strength, is practically a prerequisite for success.