johnny_rico
one more turn addict
Guerrilla 3 gives +25% hills attack and a 50% withdrawal chance. Since both Celt leaders are charismatic, it's easy to get guerrilla 3 with the Gallic warrior.
Wow! +50% withdrawl. You could get some Horse Archers with some insane withdrawl percentages. With the Dun, Barracks, and Stable, you're looking at 6XP HA with guerilla 1 out of the gate. Add guerilla 3 and they should have 70% withdrawl if I'm reading that right. I realize the HA is not a UU, but that's still nice. With the Great General withdrawl promotion, you should be able to make a unit that can't die when attacking, i.e. 100% withdrawl.