My opinion is that a bird is a bird. If your dog is doing what you want on the planted birds, using a rooster won't make a difference.

As for hunting roosters, yes, they are much different than hens. I've had them hold for my dogs -- and I use Chessies -- run for the horizon and flush wildly. Roosters do what ever it takes and they can change from one day to the next. That's why everyone has a love-affair with them.

Not sure I would hobble one. If the rooster spurs the dog in a controlled enviornment, it could cause other problems. I would continue exposing the dog to game birds and when the time comes -- season opener -- let the dog do what it has learned from your training. It should all come together whether you used roosters, sharptails, woodcock or pigeons. Like I said, a bird is a bird and I've never had to expose my dogs to a particular bird before hunting them.