When Willie Fritz was hired to take over the Houston Cougars football program , everyone knew success would follow him, as it has at nearly every stop of his long and illustrious career as a head coach. No one expected it to come so early, including some love in the rankings this past season. Now is the time to build on that, though, and finding a way to sustain success in a Power Four conference isn't easy either. The Cougars seem primed to be successful on offense, especially with a veteran group, but the defense has question marks. So what three things did we learn about the Cougars during spring camp? 3 Things We Learned Houston Cougars defensive end Brandon Mack (4) celebrates his sack in the first quarter against the Arizona Wildcats at TDECU Stadium. | Maria Lysaker-Imagn Images The Trenches Are Deeper: College football is often decided in the trenches, especially at the power four level, where players are bigger and faster than anywhere else in the sport.…