Late Roman Unit Sizes

[Flavivs Aetivs]

The Late Roman army is still fighting with missiles and swords.

Sorry, couldn't resist.

Hypothetically, if I decided to define the units of the Lanciarii and Mattiarii as light armed infantry, could I get away with calling the heavy infantry scutati?

The term Skoutatoi was the same as Comitatenses AKAIK.

Its not clear if the Legiones has integral skirmishers attached, but I would say they did. The Notitia lists several units whose titles imply they were skirmishers, so they could be separate. Troops who were detached as expediti were expected to travel fast or swim across rivers, or climb mountains, and all troop types could be detached in this manner, cavalry, legionaries and auxilia. This is a good example of how versatile the Late Roman army had become.

The Strategikon of Maurice would imply that each unit had it's own division of Lanciarii.