One of the major things that Death Battle got wrong in this fight is that Alucard's regeneration is far stronger at its base than most people think. He doesn't actually have to expend a soul unless he would otherwise die, which only happens if his heart is destroyed. We see this in his final fight with Walter, where he is clearly regenerating despite losing all of his souls against Anderson. With that in mind, he's actually far, far harder to kill than they gave him credit for, and killing him multiple times within the use of his time stop would only count as one soul regardless, because his body can't regenerate. He can also be far more clever and harder to catch than they give him credit for. Finally, the difference in AP between the two is massive. Vs Battle Wiki (not the best source) puts Alucard at Large Town level while DIO is only at Large Building+. And none of this is even mentioning Schrodinger. I just feel that if you really interpret the characters properly, Alucard would be able to land a hit eventually despite the speed difference (which I think is also overblown) and that would pretty much be the end