No question that shorter rods feel a lot lighter than longer rods. First, they ARE lighter because there is less material going into them. Second, they FEEL lighter because the center of gravity is closer to your hand. The rod has less inertia to overcome when casting it. I'm sure an engineer could explain it better than I did.
I have found the same thing you did on the flies. Bluegills love the reverse hackle flies. Try fishing three or four (if legal in your state). You'll catch a lot more fish, partially because they have better chance of seeing one of the flies if there are several in the water, and partially because they see the reaction of other fish and become competitive. You will also catch doubles.