Legate/Tribune helmet hunt

[Tarbicus]

Why are these attributed to tribunes and legates? Is it Hollywood? I can't think of a single representation of a tribune, legate, or even Emperor wearing one of these, but plenty of Praetorians and unallocated troops.

Here's one of a Praetorian tribune, on the left. His 'herculean knot' tied at the waist indicates his status as a tribune or legate.
But, then again, all the soldiers surrounding the emperor are wearing attic helmets. This instance is repeated on several panels on the Arch of Constantine - the emperor is always surrounded by soldiers (i.e. Praetorians) wearing attics. So, this could be evidence, however meager, that the attic helmet was worn by the Guard and their officers.

~Theo

Still not convinced Theo. Looks similar to the other helmets. The question is whether the brow plate was separate, or hammered from the bowl. We have dug up examples of the latter, but still no extant examples of the former.