heavy cavalry engaging heavy cavalry

[Nathan Ross]

the panegyric speaks of Maxentius' cavalry, which normally would be "invulnerable", being beak and on the head and falling off their horses, which would imply that Constantine's mailed cavalry were using the clubs..

Luckily we have the whole text available in a good modern translation:

In Praise of Later Roman Emperors: Panegyric IV

I admit that when I first read this I'd assumed that the Maxentian clibanarii were charging against Constantine's infantry, which parted to let them through. But in fact it does make more sense as a cavalry clash - Constantine's own 'mailed cavalry' (Cataphractos equites in the latin, so also heavy cavalry) performs a manouvre quite similar to Aurelian's 'feigned flight' in the Zosimus passage (this and the clubs might suggest a dubious connection between the two descriptions, as others have suggested here!).

However, the identity of the clubmen remains obscure, I think. They may be the same as the cavalry, but our men assailed those who were delivered to them with clubs implies that somebody else had done the 'delivering'! I would read this as suggesting that Constantines cataphracts had opened their line and allowed the Maxentian clibanarii through, 'delivering' them to another body of troops, perhaps infantry armed with clubs, stationed behind them.

But you're right that the blows are delivered to the head. We might assume that the clubs were quite long, maybe?... :unsure:

Here's the latin text, to check nuances:

Panegyric IV Latin Text