The important part of new troop design is to ask yourself, "Why do we need this new troop?" and then, "How would this troop affect the game?" Your troop is not a half bad idea, but if you could dig a little deeper and answer these questions, I think you'll find more people getting on board to vote you up. Read the stickies at the top of the forum. They have layouts to help you answer these questions.
Personally, I think the troop sounds too much like the Grand Warden. He already has a pretty awesome aura buff, so I don't really see the point in making another more disposable aura support troop.
Here's some other things to consider:
- What is the aura's radius?
- Will the movement buff push troops outside the aura?
- Will the buff be instantly lost when the troop leaves the aura?
- Is the buff stackable?