Uniformity

[A_Volpe]

Not a silly question.

This is a tricky question to address, as we just don't know with 100% authority on what's going on with the Romans at any particular time.

The idea that ancient Romans are "just like" modern armies and with modern uniforms, etc, is a modern thinking and is misleading. There are times, as it seems, that Romans tried to "standardize" what kind of gear they were using (as you mentioned, Marius), but, the problem is people are questioning that conclusion and re-research seems to draw up more questions than answers.

Romans, as far as we can tell, did not have what we think of today as a "uniform". That concept of every single soldier wearing identical clothing and weapons, gear, is a modern concept. That's something that started to become a thing in the 1600's. There are moments in time where there are small units of "bodyguards", "personal regiments", and Gendarme sort of things where the whole unit wore identical, distinctive uniforms, but that doesn't seem to necessarily be the case with the Romans.

As you mentioned, there were times where the Romans appeared to have tried to be standardized, but, it didn't last for long or was never really achieved. There is just too much variation in the details of the archaeological records.
There is also nothing that shows up in surviving literature or records (like Ostraka or Papyrus, wax tablets, etc) that mentions anything to the level of detail in uniformity of gear like we have had in the past 200 years. (and trying to maintain "uniformity" has been exceedingly difficult for armies to maintain anyway for 200-300 years). Nothing has been found that says anything like "This Legion on this day in the Emperor's reign were issued this type of helmet to replace the old type of helmet". Compare that to records of say, American Revolutionary or Civil War, when a regiment was supposed to be outfitted with identical specific gear - that rarely happens, and re-examination of photographic evidence shows there is so much variety in gear, many times not at all matching up to the "supposed to have" standards!

There is a book called "Wearing the Cloak: Dressing the Roman Soldier", that mentions the Oxyrhynchus papyrus found in Egypt, that mentions "55 Syrian coats" dated around the 2nd century, intended to be shipped to Leg III Cyrenaica which had moved to Syria from Egypt around that time. Ok, so, there's some indication of a bulk-order of coats or a specific style. But, what the heck is a Syrian style coat, and were 55 ordered to supplement an earlier order or to furnish newly transferred soldiers? Was it to replace old/"obsolete" gear? Was this "standard practice" or an exception? We have NO idea!

Roman records seems to follow a pattern of being kept if there is exceptional or rare instances of things. The mundane, every day boring stuff that everyone wouldn't have taken a second look at, got trashed, burned or destroyed, lost to history. Incidentally, the vast majority of these records turns up in trash piles….But these may have been "temporary" records and notes that were then transferred to "permanent" records that have since, ironically, been lost…Or…Haven't been found yet!

So now there's this idea of "standardization" - That does seem to be what the Romans were trying to achieve for much of the time.
"Standard" gear is different than "Uniformity" - That each Legionary ought to be equipped with some kind of body armor, helmet, sword, shield, spear/pilum - but nowhere has it been found that says what -specific kind- of gear. The Romans never distinguished between a "Mainz" Gladius and a "Pompeii" - That's what we call them now. The Romans didn't seem to care one way or another. They didn't seem to specify between body armor types either, none that I am aware of. "Lorica" seems to show up in the imperial period meaning "metal body armor". "Lorica Segmentata" is a modern term. We have no idea what the Romans called it.

But, we have a problem as modern historical re-enactors….There's only so many [helmets] that have been found. If your group is trying to be as accurate as possible and copying actual artifacts down to the minuscule details, you're going to run out of "variety" rather quickly, so, we end up having to look sort of "uniform" no matter how hard we try. But IMHO it is "better" to have a lot of very accurate copies of a handful of items, than to have hundreds of "inspired" or "looks close enough" or "looks to us what we like to think they might have possibly had" gear.

It also depends on what time period you're looking to portray. In the Republic, the army comprises of men who own land and have a particular social status, which then determines where they are in the ranks, and what kind of gear they are supposed to be able to equip themselves with as part of their rank and role in the army. So, gear was probably quite varied, as some of it may have been handed down from father to son, but oddly enough, the Montefortino style helmet, which is thought to be the most common helmet in use in the Republic period, archaeologically are nearly identical to each other in shape, style and features, and appear to be unchanged for almost 200 years. In the Imperial period / Principate, there seems to be a huge variety in helmet styles and types (although the vast majority seem to share common features and shapes ~ brow guards, neck guards, "crest" rings) then as we get to the Late Empire period, gear seems to look "similar" again.

Whichever way you look at it, there is still more to uncover (literally) with these Romans. What we thought we knew 10, 20 years ago has undergone a complete change with new discoveries and re-examination of existing finds. They appear to be "similar but different".