Artifact sets to reduce army salary :
One(or two) units type based armies might be a good choice once you start getting big.
There are two lvl 2 art sets in game that reduce archers (Sniper Set) and warriors (Warrior Set) salary by 40%.
You can equip those on guru to add to 'Spirit of Altruism' Skill which reduces army salary by 20%.
This way you can manage more main units without salary increase, and train your army faster.
Both sets have boots that reduce training time by 30% for specified unit on top of that.
