This guide is how to get the achievement in the fastest way possible.
Select the 'Enemies of Rome' campaign from the single player menu.
Start up each part, press enter and type "home run". This in-game, dev created cheat will auto win the current mission. It isn't looked at as cheating in the eyes of TA as no files are modified and no "trainer" is being used to trigger the achievement.
Rinse and repeat until you get through each step of the campaign.
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If you'd like to get through each level legitimately, be well prepared as even on easy the CPU AI tends to rush.