I think we can stay with Christos' current system of traits. Basically he has different "upgrade lines" with 3 tiers each. The "Experience" traits ONLY give attack bonus at this moment, and making all such traits only affect attack bonus for units would be a "simple" design trait.
The Base Traits said:
Speecher (Gives you more chances to have success in a speech)
Good eye (Gives more chances (20%) of seeing an enemy trap)
Brave Commander (Gives better chances for a successful all out attack)
Infantry Commander (Gives better chances to have an increased Attack when commanding Infantry)
Cavalry Commander (Gives better chances to have an increased Attack when commanding Cavalry)
Artillery Commander (Gives better chances to have an increased Attack when commanding Cannon)
There are 3 "Unit Experience" traits based on leading units well and give purely attack.
There is a "General" trait (Brave Commander) which gives attack to any unit, but only for all out attacks.
There is 1 "Natural Variable" Ambush spotting trait, which will help prevent traps events and counterattack events for charging units.
There is a "Player Variable" trait (Speecher) whose effectiveness is based on how good a role player the commander actually is; a great speech's effectiveness would probably be increased to a higher chance than a bad speech, if a bad one even gets a chance to start with.
In going with this, possible other traits you might like while fitting with what you have so far.
Jogger/Runner/Sprinter trait will increase
Run Speed and therefore
attack for Cavalry and Column-Formation units, while only run speed for Artillery. This is gained when players utilize Run/March orders effectively. Also, I want my horse artillery.
Stubborn/Stone Wall/Mountainside will increase
Attack when a unit is
purely defending. (best for Infantry, possible for Artillery). This is complete opposite of Brave Commander, and is gained when a player conducts very strong defenses against large attacks.
