Battles of the late Third Age

[Kuruharan]

Like what, exactly?

Like the things I listed immediately below my statement.

It seems (at least to my mind) that the Gondorians were quite definitely oriented towards heavy infantry.

And I tend to think the Gondorians were a more well-rounded force. I inquire regarding your source.

I would disagree with this statement, and instead posit that a fully armoured knight in plate was the most effective.

Ahh, well fortunately this is not a matter for which we have only theoretical speculation upon which to rely. We have a grand instance of this very confrontation in history.

The Mongols shot up the heavily armored knights of Europe just as effectively as they shot up everybody else. As a matter of fact, they made the Europeans look like a bunch of blundering buffoons and the medieval European military system as a whole look (to put it gently) "incapable."

Of course, those silly Mongols did that to most everybody. Darn those well-armed horse archers.