Board Thread:Warhammer 40k General Discussion/@comment-4851119-20140118095944/@comment-8881468-20141220185718

marines of other legions did not get absorbed into the ultramarines... they would always stand out as being from another primarch.. also: how do they pass on their genes in competition to those of guilliman and so on... we debatged this somewhere before.. it is simply not feasible if you have a basic grasp of genetics and common sense...

ultramarines were merely big because guilliman was a good administrator and they pretty much ruled over more recruitment worlds than any other legion