Making a wookiee vehicle isn't so simple as making a wookiee and giving it a player animation.

It would have to be a walker vehicle, thus limited to run, walk, and crouch, most likely would have only 1 visible weapon... And couldn't jump.

The wookie would then have to choose between:
A) Walking/floating on water like our speeders do
B) Being invincible to water allowing them to walk around anywhere
C)Not being able to enter water at all

Then as a vehicle, players would have to spawn into them, so we would have wookiees standing around at main bases?

Among other limiting factors, this would never really work out.

As for Ewoks, that would be more like an easter egg type thing... people possessing Ewoks is just odd.

"Munchkin: One who, on being told that this is a game about politics and intrigue in 17th century Italy, asks to play a ninja."
— Andrew Rilstone