The lost Primarch.

Ok this topic is for those of you who play warhammer and Wh40K.

I am just throwing some ideas around here UTTER speculation and only minimal proof.

Anyway, I have heard before that the warhammer world is located in the WH40K universe but the high level of warp activity surrounding it and on it makes it hard if not impossible for anyone to reach it. Whats the basis for this claim? Well first the presence of the chaos gods, mutants, beastmen etc appearing in the same way they appear in the WH40K background (I know its also a case of company branding but enough of the real world....). Second the shared mythology of the Old Ones third. Remarkable similar races (at least physically) appear in both backgrounds Orcs Elves Humans dwarfs halflings etc.

Anyway where is this going?

Well complete stab in the dark here but remember that there are two Primarchs that are lost? I think I may have found one.

Anyone on the warhammer world resemble a Primarch?
Changed an entire culture?
V.young when he killed his first great enemy?
Defeated many enemies nearly singlehandedly?
Human?
Worshipped as a god?

Is it just me or does SIGMAR sound like a Primarch?

Perhaps he was cast onto the one planet the Emperor couldn't reach him?

Throwing the idea open don't know if its true, doubt even GW has thought of this before but it would put an interesting perspective on both games backgrounds if it was the case.