Complex sentence: Marine Corps officials have stated that they continue to use Stann's story as a recruiting tool, and he attributes his success in mixed martial arts to the foundation he learned fighting at the Marine Corps Martial Arts Center for Excellence in Quantico, Virginia.
Split into simpler sentences: Marine Corps officials have stated that they continue to use Stann's story as a recruiting tool. He attributes his success in mixed martial arts to the foundation he learned while training at the Marine Corps Martial Arts Center for Excellence in Quantico, Virginia.