The scenario would also require that the Armada have the ability to actually transport the Duke of Parma's army to England or that the Duke, after being put on short supplies and wages for more than a year while the Armada kept being delayed, have set up facilities to produce such naval transports...and the crews required.
Well, he did have some form of that prepared, but I don't know from memory how exhaustive (and the book I read this in I checked from the library, so I can't look it up).