The question is, what actualy can the English Armada accomplish? Can it be a threat to Spain itself? No. Can it capture some of the Spanish islands? Maybe, but permanently? I doubt it. I don't think England is strong in this age enough to defend them against Spain indefinately. Can it accomplish Portuguese independence? No, I don't think so either. What it can do is provide a distraction. I beleive that in these days both France and the Netherlands were fighting Spanish troops. I think there lie the permanent changes. Maybe this causes the Spanish to be distracted enough that the Dutch manages to do slightly better in their war against Spain (this was the time during which the Dutch started to be able to manage to push back the Spanish forces). Less Spanish troops to defend a city, because they are needed elsewhere or one more mutiny of Spanish troops because of lack of money, could mean the Dutch manages to capture a couple more cities than OTL, pushing the border somewhat more to the south (for example they might manage to connect Ostend to the rest of the Netherlands and thus keeping it Dutch and protestant). I have no doubt the same is true for France, although I know less about the wars of religion.