heavy cavalry engaging heavy cavalry

[Timianus]

IIRC (hazy memory from college) 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. That is also consistent with the tactical situation of Constantine pulling his cavalry from the wings to come around behind his line and surround Maxentius' heavy cavalry.