The size of a typical legion varied widely throughout the history of ancient Rome, with complements of 4,200 legionaries and 300 equites in the republican period of Rome, (the infantry were split into 35 maniples of 120 legionaries each), to 5,200 men plus auxiliaries in the imperial period (split into 10 cohorts, 9 of 480 men each, plus the first cohort holding 800 men).
There were ten cohorts including the "prima cohors" in a legion. A full-strength legion contained 6,000 men though it was not uncommon for most legions to be undermanned due to previous battles. All of these numbers depended on the date
I also played Defender of Rome, on the PC (I have an emulator version kicking around here somewhere
). For some reason I remembered reading somewhere that a century was 100 men, and there were 100 centuries in a legion. Apparently those numbers are somewhat off.
But still, since an army usually consisted of several legions, and it was in fact not uncommon to see armies of 20k-40k or more, there is a bit of a scale disparity.
Though one could say each of our troops represents 50 men or some such thing, but I find it odd that all 50 of them lost an eye.
And danke Edi.