Enemies

[Raynor]

Saying that someone's language is not language but merely "the scream of birds and the bellowing of beasts" goes way beyond mere dislike.

I don't have the books handy, but it seems like they are talking about war cries. If I am correct, and I will check later, then, generally, war cries are pretty much consistent with his description; they are intended to sound "savage" and instil fear. This would only strengthen the accuracy of his description and diminish whatever fears we might have of his racism, based on this quote.

Not clear at all what happens in between.

In which case any presumptions that the rohirrim killed weaponless orcs are mere speculations, matters of personal opinions.