Late Roman Tactics

[PMBardunias]

There seems to be two versions, one a 'moving' fulcum, and 'stationary'. The rows of shields can be up to to three - one rank kneels, one rank stoops, one rank guards from overhead.

How would you describe the "moving" fulcum? Rance describes a system of two layers of shields advancing in the face of missile fire.

As I gave as a disclaimer, this is not my time period, but I recall that there was "pushing with the knee" at Strousbourg I think. Would these have been front rank men kneeling? I have seen hoplite reenactors trying to borrow this concept , wrongly in my opinion.

Also, I find the evolution of this formation in the roman context interesting. Is there evidence for the testudo formation used in sieges, etc. predating the use of the fulcum on the open battlefield? It would seem to me that most shield-wall formations evolved as spear armed infantry developed closer order tacics, but in the roman context I wonder if it was the borrowing of a fully formed anti-missile tactic from one context and applied to the opened battlefield.