@ThaneAquilon Quite possibly, but most humans, even in the eye, don't live for a couple hundred. The ones that do are not the ones doing the boarding I assure you, but commanding empires and armies. Good point on the marks.
As a note against chapter specifics like better boarding, note that the conqueror comes with a khorne berserker HORDE, which counts as regular CSM ruleswise, despite the fact that I would put money on a HORDE of khorne berserkers being better off in a close range melee/shootout that a couple of serfs, even with a dozen marines. Devil's advocate, I am today.
Also seems strange that a couple hundred serfs fight better than several thousand/dozens of thousand orks! I mean the things survive getting their arms torn off and hard freakin' vacuum for minutes, added to the fact that each one is stronger than a human by a mile, and a close up melee between humans and boatloads of orks should be like a full grown man putting a kitten into a blender and pressing puree.