Real life has been kicking my butt for the past few weeks. I'll just post a few quick thoughts to try to get caught up.
I've never delved deeply into it, but I'm pretty sure that the subject of orcish origins and reproductive mechanisms is not all that clear-cut. It's up there with Elvish ears and Bombadil and such -- though I don't think spawning from mudpits was ever a variation Tolkien contemplated. There's at least one old thread I recall,
Orcish Fëar, which gets into the more arcane depths of the controversy. For a more primary source, see the "Myths Transformed" section of
HoME X - Morgoth's Ring.
One thing that strikes me right off about this sequence is the
Dutch angle at 1:08:55, when Saruman is "communing" with the palantir -- the odd angle is more typical of horror films or stylized Hitchcock thrillers. This is just down the road from the push-in/zoom-out shot (another Hitchcockian technique) on the road at 53:24. These sorts of shots hark back once again to PJ's horror roots, and signal again a more dreamlike, stylized approach rather than a more realistic, "historical" approach. I mention this because I recall from very early publicity -- like around the time the deal for the movies was first announced -- that Jackson often mentioned
Braveheart as a point of inspiration for tone and style, specifically citing its
"historical authority" and contrasting it with more fantastic movies like
Willow and
The Dark Crystal. For my money, Jackson could have tilted more towards a historical tone than he ultimately did, but I realize that's a matter of taste.