Roman swords vs Greek swords

[M. Caecilius]

For such wounds to have been inflicted I would expect either a terrible unconventionally packed melee cavalry action or the Romans hacking at fleeing Macedonians who had fallen off their horses.

The latter is more or less what I had in mind - whether or not the Macedonians had already fallen of their horses or not. Your point about javelins is well taken.

Infanry skirmishing action on rough ground with one side trying to keep their ground... an attack against fortifications... Now there is where I would expect to see such single combat action and probably such wounds.

Wouldn't this involve the cavalrymen (provided again Livy knows what he is talking about, but in order to have any discussion at all, we will have to trust him that far) to be dismounted? I can only with difficulty see infantry reaching shoulders of mounted men with their comparatively short gladii, even from the elevated position of fortifications; if those cavalrymen have already dismounted, the situation would be different.

I should note that I have no practice in sword-fighting, so I'm always happy to be corrected by someone who works from a less theoretical level and has hands-on experience.