Old school link..
Last time i checked, the whole Sigmar story was a way to potentially link WH fantasy with WH40k, with Sigmar being one of the lost primarchs, and the fantasy world being lost to the rest of the galaxy by surrounding warp storms. but with that being effectively killed off with the new editions (3rd ed of 40k i think is when it happened officially?) and the heldenhammer explanation that Ancient Tiel referred to coming into existence, that dream died. the only reason i mention this is because the original sigmar story that hasnt really changed for continuities sake doesnt really place him as the lizardmen god...tho i could be wrong, what with me not being a fantasy player lol.