I really enjoy the wood elves campaign for the most part... but the long victory condition is mostly annoying instead of challenging.
You need 8 rituals completed, each takes 10 turns and you can only have one running at any time.
This means that by the time you've already won (confederate/capture all the trees, defeat chaos, forge a big alliance that steamrolls everything, etc), you may still have to pass 30-40 or even more turns just waiting for rituals to clear. Depending on your PC, this can include staring at the end turn progression for a pretty long time, without anything fun to do as a reward.
My suggestion is to either reduce the time it takes to finish or allow us to start multiple rituals simultaneously (for example after defeating all spawning threats). You can also increase the difficulty of encounters when several rituals are running to add some danger or have more armies spawn periodically as an additional challenge/something to do.