You've distorted the main stock too much. Try holding the shift key next time when resizing your image.
Avoid using more than 2 main renders, especially if it's the exact same one... a more effective and similar effect would be to lower the opacity of the faded image even MORE and then placing it closer to the main focal, just so it only slightly shows - like a shadow.
To be honest you should ditch the existing background and find a better substitute, using blending techniques to help them merge together.
Another stock or c4d would definitely benefit you aswell...