User blog comment:40kfan/Centurions: Your Thoughts?/@comment-8464494-20131220190432/@comment-5112067-20131220214745

Going into that "will pale in comparison to what a few hundred Space Marines can do. Because their better than anythign else the Imeperium can bring forth. Thats just how it gose." . Oh really? Can a few hundred Space Marines defeat billion of Orks and take control of the world after defeting them? No, no they cant. Space Mariens play a support role in battle, they support the IG, their assualt troops not a  general combat force.

Allow me to give you a real life example to further solidate my arguement, lets say that America went to war with another country that had equal forces, no nukes are on either side so its just fought conventially. Would it be the marines that would win America the war? Hell no, it would be the air force followed by waves of tanks and infantry, the marines are just used to secure a beach head. That goes straight into 40k, replace the air force with ships, the marines with Space Marines and the tanks and infantry with Imperial Guardsmen.