In my coven we have 13 positions, 2 casted circles and names that do not match normal covens.
Earth is not the same as wood for us. Wood is the female side of earth, and earth is the masculine. Wood is everything that grows, earth is the base for that growth.
We have nine elements all together in the first circle; earth, ice, air, lighting, fire, metal, water, wood and spirit.
The second holds five; earth, air, fire, water and spirit. These are elements called warrriors, they protect the inner circle.
Spirit for the outer circle, and spirit for the inner are connected. The inner is the female high crone (high priestess) and the outer circle warrior sage (high priest) make up the goddess and god.