When you ask "How can you be a road course god but mid on ovals?", I have the exact same question. Road courses are a lot more challenging than ovals. Road courses have more frequent turns, sharper turns, and dramatic changes in elevation. So if you can master road courses, ovals should be a piece of cake.
I'm not the least bit surprised when race car drivers who are great on ovals have trouble with road courses. So when Tyler Reddick won at COTA, I was impressed and amazed. He'd won the Daytona 500 and the EchoPark 400, but those were both oval courses. By winning at COTA, he became the first driver in NASCAR to win the first three races in the regular season. Yes, fhe Daytona 500 is the biggest race of the NASCAR season, but winning at COTA is more challenging and impressive than winning the Daytona 500.