Khmer.
No building prerequisites to age up means you don’t have to clear room for the buildings. This is a double bonus because you can age up even faster than normal AND you have more room for farms and production buildings so Booming is faster.
Teleporting farmers means you can place a farm wherever it fits, without caring about proximity to Mill or TC.
When you decide to get aggressive, the Ballista Elephant is the only unit that can cut trees in Castle Age.
Boom up with super farms, cut trees with Ballista Elephants, then spam Light Cavalry through the gap.