Not to add fuel to the fire, but I think Jovid's point is valid.
Although I don't understand where his math is coming from, I think his point is that after the F1 generation, you dont know what percentage you have. When you cross two baldies, you are most likely to have to have a 50% angus 50% hereford but you could (correct me if i'm wrong), genetically, have anywhere from 100% angus genes to 100% hereford genes. Parentage wise, you have half the genes from the sire and half from the dam but breed wise you really dont know.
It looks to me like if you had two animals that you knew for a fact were each 94% gelbvieh then, when mated, their offsring would be a minimun of 88% gelbvieh but would most likely be 94%.