Just today rec'd Legions of Rome-the Definitive History of Every Imperial Roman Legion by Stephen Dando-Collins, published in England last year. The price in the dust jacket is 35 Brit pounds, but I got mine new on Amazon for $40 including shipping.
The subtitle is deceptive because a lot of the legions that served in the imperial years were raised beforehand and they are included in the book even tho technically not imperial.
Have only spent three hrs or so w/ it, but so far I'm impressed. It has substantial pages dedicated to each legion's history plus detailed sections on organization, battles, etc. It's ~600 pages. The most interesting thing for me so far tho is the shield designs which are illustrated in color for all those which could be identified. I tried repeatedly tonight to scan those pages in, but for some reason my HP won't do it. I think it's an old HP vs. new Windows 7 problem. If I figure it out I'll add later.
The striking thing is that only four of the designs bear any resemblance to what we think of as the standard shield emblem, the out speading lightning bolts. The author claims that this error has come down thru antiquity due to Trajan's Column where all the legionaries depicted carry this design or one slightly modified from same. The reason he attributes to this inaccuracy is that the only legionaries allowed within the precincts of Rome at the time of construction would have been Praetorians. The Praetorians did have the lightning/thunderbolt design on their shields and many Praetorian cohorts had a slightly different style of same. The sculptors of the column would have used Praetorians as models and assumed the whole army was fitted thusly. But what did they know of such military details? They were artists not legionaries and who else in Rome would know the difference save some relatively rare frontier veterans who would likely not have seen the column until completed? It makes some sense to me, but who knows.
In any case, I'll try describing the shields for our RS2 legions absent my current scanning capability.
Hammata
I Germanica-red with the Pompeian Lion in gold holding a sword vertically in its right paw.
II Augusta-gold w/ veritical red stripe, white currlicues in corners, white pegasus and antelope flanking boss.
III Augusta-red w/ gold lion's head facing right.
III Gallica-gold w/ white mer-unicorn atop boss and three white bulls below.
V Alaudae-red w/ two gold elephants atop boss and three below.
V Macedonica-gold w/ large grey bull
VI Ferrata-same except bull is red
VI Victrix PF-green w/ white bull
VII Claudia PF-dark gray w/ red bull
VIII Augusta- red w/ gold bull
IX Hispana-dark gray w/ white bull
X Gemina (Equestres)-gold w/ red bull
XI Claudia PF-red w/ silver lightning bolts interspaced w/ tridents
XIII Gemina-red w/ gold lion with starburst halo
XIV Gemina-red w/ gold lightning bolts interspaced w/ eagle wings
XV Appollinaris-red w/ large gold palm frond
Segmentata
I Minerva PF-white w/ multi-colored gorgon head
I Adiutrix-gold w/ large white pegasus
III Cyrenaica-gold w/ large white bearded head assumed to be Jupiter
IV Sythica-gold w/ white bull
IV Flavia Felix-gold w/ rampant red lion
X Fretensis-red w/ white bull atop boss and bireme warship below
XII Fulminata-gold w/ silver thunderbolts
XIV Flavia Firma-none shown
XX Valeria Victrix-red w/ three white arrows emerging atop boss and gold boar below
XXI Rapax-gold w/ red vertical stripe and white boars flanking boss
XXII Deotariana-gold w/ large red eagle
XXII Primigenia-red w/ gold eagle
Praetorian-light purple w/ gold thunderbolts interspaced w/ eagle wings.
The predominance of bull designs the author accounts to the popularity of bulls and bull fighting in Spain even then. So legions raised there or which spent tours there adopted the emblem.
He bases his designs on various sources, legions' specific coinage, coats of arms found on barrack lintels, grave stones, etc. As I said I'm only into this a few hours.
I'm not campaigning for the dev group to effect these changes in some future patch. In fact most of the depictions are quite primitive compared to our more intricate designs. I probably prefer ours actually. I just found it interesting and thought some of you might as well.