It very much depends on what your identity is, and who your enemy are.

If in charge of a phalanx battle-line, I play very defensively.
If in charge of a Celtic or Roman line, I play offensively.
If in charge of a Nomadic battle-line, I fight evasively.

This is how I fight with an army, but I often have cavalry skirmishes to wear down sighted armies before engaging, which can be done without any losses to your men, and thus the enemy can suffer a loss of one third of their army before they even reach your line.