Recently picked up one of my favorite childhood games and practiced a bit.
Here's how to consistantly beat an extreme AI:
1. Pick "Cumans" civilization
2. Follow default build order until feudal age (6 sheep, 3 wood, 1 boar, etc.)
3. If you found sheep & boar directly scout enemy main gold and protect it with scout
4. When you click feudal age send at least 4 villagers to enemy main gold
5. When you reach feudal place a town center at enemys main gold (protect villagers with houses/barricades)
6. Let villagers shoot enemy from town center the whole game from now on
7. Build siege workshop and siege units (you need blacksmith first)
8. From here on you can do whatever you like to beat the enemy, i like to get to castle age first before hitting him hard, but you can also siege in feudal age as he is weak from this point on
9. Profit