Carrion Woods

[Fantomen]

Also early game a dryad with a few (like 5) dryad hoplite bodyguards can take most indies if given a hide shield (preferably two) and scripted bless/barkskin/hold/hold/spells or a bit later bless/protection/protection/hold/hold/spells. The dryad will cast mostly tune of fear which makes your awed units near untouchable and eventually routs the enemy. Just watch out for crossbows.

Thats the most effective expansion force I´ve managed at least and you can make one per turn quite early.