Board Thread:Warhammer 40k General Discussion/@comment-4851119-20140118095944/@comment-6078851-20140118134516

and let's not forget the genetic engineering aspect - astartes are created using the genetic materials of their respective primarchs. so while some will have differences from their original genes, astartes are essentially mini-primarch clones, and the genetically engineered, and superior, primarch genes are the dominant set and will always show through. astartes ought to look more like their primarch than any child from a biological parent.