Why are the bread and wine consecrated separately at Mass, and does a death occur at the altar?

Most people say the separate consecration of the bread and the wine represents the death of Christ, and that is the standard answer, but I think there is a little trouble there. The bread really and substantially changes into the body of Christ, a true transubstantiation, but there is no real, substantial death at the Eucharistic table, because Christ cannot die again; he can only die once, at Calvary. So the separation of the two consecrations creates a symbolic representation of death, not a real death. You feel compelled to have a death because you are trying to make the Mass the same sacrifice as Calvary, but the death cannot really carry over, so the Church settled on representing it symbolically by consecrating the body and the blood separately. That is good enough for me. Some theologians still question whether there should be a greater representation of the death, what they call a mactation, but the Church has settled the issue this way.