Rocking denim on denim rules: anything hard and fast?

Headed to a rodeo and doing a bit of cowboy cosplay (self-admitted city slicker here) but my only western style shirt I currently own is denim. I’ve never had the balls nor occasion to rock a Canadian tuxedo before, but want to give denim on denim a try. These are my usual jeans I wear with my boots, but I can’t tell if the outfit works or not.

Any hard and fast rules on stacking denim?