Send a peasant into a training building (like a Dojo or Sharpshooter's Guild) to turn them into a tier-1 unit. Send that unit into a different building to upgrade them to tier 2, and so on. 2. Yin, Yang, and Zen Masters Battle is the only way to get ahead.
Geishas are your healers. Always have them, but keep them behind your front lines as they are fragile. battle realms
If you stay in your base, you won't earn the points needed for late-game units. Harass enemy peasants to disrupt their economy and farm Yin/Yang. 3. Choose Your Clan and so on. 2. Yin