Legionary Equipment During Reign of Marcus Aurelius

[Nathan Ross]

Vegetius' semi-spatha.

The semispathium in Vegetius is always carried with another weapon, either a spatha or a gladius (probably the same sword, in reality!)

So I don't think we need to look any further than the pugio - perhaps the larger 3rd-century variety- for what he is describing here.

the equipment of legionary of the middle to the end of the second century were NOT inferior to earlier periods...and arguably were superior.

Absolutely!