This sequence generally works, but one problem with PJ's version
is seen here (time sequence). Even forgetting the bizarre
uruk-hai "births", it takes some time to create and meld an
army. To do it virtually instantaneously as in the movie
stretches credulity and "suspension of disbelief." And
wouldn't female orcsees make quite nassty amazonian warriors? Perhaps riding wargs?
Not the pumped up movie wargs but the book types, which I see as more wolves on steroids then the PJ's giants.
One movie bit that was quite well done was Saruman's brief
pondering of his chat with the eyeball before he acted. It is
just about the only (granted implied) movie Saruman doubt.