Battle Tactic: Shield Wall with Moving Flanks
Mediolanium, where there is well enough money to get one really good defense... In those cities I use this innocent little tactic (Mediolanium may be to easy for this, but I took it for an example anyway...) Now, do this, if you have dinarii for it of course.
Now when the enemy reaches my front, consisting of Legionnaires, my Javelin Throwers also starts throwing... Now this is when my element of surprise comes in... my cavalries move up beside the enemy and past them, where I reorder them, and make them go to a full scale attack, the little frightened enemies have nowhere to go now, and they get slaughtered... I've actually survived 5 attacks within one year, where each and there were over 60 in every attacking army... I don't know what you think about that, but I think 240 enemies in one year is pretty good...
For enemy infantry armies, I post javelin units in front, Heavy legions behind, and have the javelin troops fire and retreat in alternate ranks as the enemy approaches, until finally they are withdrawn behind heavy troops as the enemy closes and continue firing while the enemy attacks the heavy legions. If I have cavalry, I use them to attack the rear of enemy troops are are FULLY engaged against my infantry.