First off, is it legal? I'd think so.
Second, is it cheating? Depends I guess. IMO, you'd be cheating yourself. It's called "hunting" for a reason. The challenge is where the thrill comes from for me.
Finally, I agree with the Bernie's. If the reason you want to take the compound is because you aren't confident with the stick, then practice with the stick until you are confident before taking it in the woods.
Sure, you'll likely have situations where you'll think "man, if I'd just brought the compound!" Oh well...again, that's why it's called "hunting". I was in a primitive weapons unit in CO a few years ago on an elk hunt. First day in, while getting water for camp, two of us saw a big bull 150-200 yds away on the side of the mountain, in the wide open. A doable shot with an in-line muzzleloader...but we only took bows. Did I think, "If we only had a muzzleloader..."? I probably did--but I sure don't regret not having it. I didn't get a shot on that trip, but had a great time and if I get to go back, I will still only take my bow.
Chad