well, back in the old days the image for space marines, and everything else in the hobby, wasn't as developed as it is now. over time the fluff was refined into what we know now and as that happened certain images became associated with certain forces.
in your example, early marines displayed a variety of markings which over time came to represent the different legions seperatly, so the omega symbol became the ultramarines badge while the blood drop was more linked to blood angels. |