I just thought about something...

It just seemed interesting to me that of all the class extentions picked, 3 of them took the class branch that was less/ least taken. Take Firebrands. The Flamekeepers were not revealed before CWK I's release, so they could have learned Holy magic, or heck, even an Ice Arrow. Windraiders could have taken a bow, but I guess that looked too much like the Firebrands.