In order to play RTW one should not read any history of the era, it will only cause anguish. The game supposedly has units of armoured camels, flaming pigs, and screaming valkyrie barbarians for heavens sake! History be damned.

Avoid 'I Claudius' like the plague, its way too cerebral.

Instead, watch action movies like Gladiator, Spartacus, Ben Hur, etc and read novels on the same theme. You'll be happier in the end.