They are both special, but let me ask you this, care to comment on the Legions view of human life, how careless it is with the life of its non-veteran troops? Just surviving being canon fodder for over a decade would be impressive, but these guys went above and beyond, killing hundreds of enemies and pushing forwards with every attack, earning the right to be called a Centurion.
(You know, a Centurion is only level 12)
But, I have killed 20 (maybe more) of these great "hundred killing" men called Centurions. (If there were more Centurions in the the wastes, I would have killed about 100 of them)
I have killed 30 (maybe more) of the great "hundred killing" men called Veteran Rangers. (I just started killing Veteran Rangers in Camp Golf, but that House Resort is still a challenge.
I have killed thousands of warriors, therefore, I earn the right to be called the Legendary Courier.
I am Superior to these weaklings called Centurions and Veteran Rangers, because I'm............the Legendary Courier.
(I'm level 34)
(I can 1-2 hit kill a deathclaw from long range)
But, but, the Centurion and Veteran Rangers can be Superior to other weaklings like Fiends, Vipers, and the "Legendary" Great Khans.
(I think I have made a good drama speech above, all non-dramatic related words are in parentheses)