I've really found that you have to adjust your plans as you play each faction.
Those like Egypt and Greece really work well defensively, pressing your enemies into attacking you.
Horse archer factions such as the Selucids are great for hit and runs, attacking the enemies before they can get into a strong position to withstand you.
Romans are great as both defenders and attackers with their turtle style, yet typical roman brute force.
Germany and Britannia for me seemed much better attackers, taunt and hit.

Good luck gaiusjulii though I'm guessing by your nick that your focused on the Roman faction so far....