In the game the player can achieve the following Imperial ranks:

1. Auxiliary

2. Quaestor

3. Praefect

4. Tribune

5. Legate

After signing up you become an "auxiliary" (a.k.a. auxilia), which was kind of a civilian reinforcement of the regular Legion troops (not a fully fledged legionary), made up of non-citizens of Rome, which makes being given the title, along with Legion armour in the game kinda, dubious? "Quaester" (financial supervisor) was a civilian title. Only the ranks of praefect (a.k.a. Praefectus castrorum), tribune and legate were military ranks.

In the context of the game, wouldn't it have been more accurate to give you the following ranks to make it more accurate?

1. Aquilifer (i.e. corporal)

2. Optio (i.e. Sgt. Major)

3. Centurion (i.e. lieutenant)

4. Praefect (i.e. major)

5. Tribune (i.e. colonel)

6. Legate (i.e. Brigadier General)

IF we conclude that the Legion is, in fact, modeled entirely on Rome's legions, your argument is then entirely valid. HOWEVER, as this is a Fantasy world, what we are dealing with an organization that is more Legion-like than it is Legion.

In point of fact, I believe that Bethesda was too heavy-handed in creating the Imperials and the Legion. Just by the heavy use of Imperial names and Legion titles, we would have to conclude that Cyrodiilan language is almost entirely anolgous to Latin, which undercuts the fact that Cyrodiil is theoretically a total Fantasy creation.

Is that a diplomatic way of saying that they tried to copy the Roman legions for the Imperials, but didn't fully do their homework? Ohh, I can handle some inconsistencies. After all, it is fantasy, but it would've been nice if they had gotten the little details more accurate, aye? It would've been even better if they'd included different armour for each rank!

It could just as easily mean that they wanted to borrow from real life without copying it directly. After all, that's what they've done in all the other Elder Scrolls games.

Yeah, I think it's more meant to have a Roman "flavour" than actually be directly anolagous to real-life historical Roman things, same way the Bretons have, well, nothing much in common with real life Bretons, even their names are a mix of Irish-sounding (but not, to my knowledge, actually Irish) and French/French-sounding names. (To the extent that I seem to recall having someone on here flat-out mock me for "thinking" there had ever been "real life Bretons", much less that there's still people today who would identify as that at least as strongly as they identify as French...)

The other observation I'd make is that your character isn't exactly a military recruit. You're not performing ordinary duty; you're given special assignments. The first two levels being civilian makes perfect sense in that sense, with appointment to military ranks as one achieves something like command status.

Maybe, but they're far from looking after finances like a "quaester" used to do.

Maybe the developers were getting cute about it, and thought that "quaester" was a good-sounding fit for "quester."

Nope.

The game doesn't copy but borrows and takes inspiration from the real world stuff.