Battles of the late Third Age

[Kuruharan]

The French knights at Agincourt didn't have full plate

The battle was fought in 1415. If full plate was not around by then, please enlighten my bottomless ignorance as to when it was in use.

However, be careful. Too many more years into the future and you get into the Gunpowder Age, and my statement was specific to the ages before that really began exploding on the scene (even though by this point it was already in some use).

the majority of their casualties were caused by suffocation in the mud, and the English dismounted knights and men-at-arms.

What difference does that make? Even ignoring the fact that I disagree with your statement that plate armor could not be penetrated, your contention is that the heavily armed knight was the most effective fighter in the whole era before the advent of gunpowder. This is one of many instances where the heavily armored knight just did not fare too well.

If you would like another instance, aside from Mongols, of the mailed chivalry of France (considered for some unfathomable reason to be the best, I think they just thought they were best) "not doing too well" look at the battle of Nicopolis in 1396.

The "invincible longbow" is a quaint English myth.

Well, something certainly tilted the battlefields of the Hundred Years War in their favor against most reasonable expectations to the contrary for a considerable period of time.

*Cough* anyway, back to warfare in the Third Age of Middle earth...

Saurman's followers seem to have been of a rather plodding sort or Saruman did not encourage them to take initiative themselves. It is probably some combination of both. The Isengarders could have caused much more havoc had they reordered themselves and pressed an attack rather than drawing off in the first battle.