The last five seasons have been SMU‘s best stretch since coming back from the Death Penalty. Between Sonny Dykes and Rhett Lashlee, 43 wins are on the resume with five straight bowl-eligible seasons. Lashlee brought home the biggest accomplishment of them all, though, winning a conference title for the first time since 1984. But something was still missing for the Mustangs — being in a big-time conference as they once were. Left behind when the Southwest Conference fell apart, SMU has been in a Group of Five conference for the last 28 years, and recent times have been spent attempting to break…