I have one addition and one correction.

In the unit section there is a tip regarding the effectiveness of slingers against heavy cavalry. Perhaps you could add that this is not only because of the armour piercing capabilities of the slingers (which foils the heavy cavalry's greatest strength), but also because the most heavy cavalry units don't use shields (because their lances are two-handed) and shields are the best protection against missiles there is.

In the last section (Economy and Infrastructure) there is a tip about roads. There it should read "(see above)" instead of "(see below)", since the strategy section is above.