Dynamic Dungeons & Raids.
I had this idea. As it stands now, Raids are a one shot deal. Each time you do the raid it's the same exact thing, win or lose.

How about, a “soft fail” system.

For Example:
The players must get the attention of a Primal leading it through an imperial base. The idea is to make it destroy the base. Steer it well and you then face the Primal at the end having taken out the Imperial base with it. Steer it poorly and the Imperial legion defeats it, and you have to face a number of imperial battles instead. This puts the less skilled group through a greater number of lesser fights, while the skilled group goes through a lesser number of more difficult fights. Depending on where you lead the Primal, the fight changes giving it a dynamic feel. The less skilled group still spends more time in game than the skilled one, and the skilled group still get's the harder fights they crave.