Another primary consideration in introduction & eventual disappearance of Segmentata?

[ValentinianVictrix]

Ammianus does talk about all forms of infantry being used in the 'expeditii' role, including 'Velites', Auxilia and Legionarii. Its assumed that the troops were striped of their body armour so they could travel faster, climb up mountains, cross rivers without drowning etc.

This is a good example of showing the Late Roman armies flexibility in combat roles.