Shogun's cardio woes are overstated. Most of the fights where he gasses, his opponent is just as gassed as he is, leading me to believe that his cardio issues are a direct result of his aggressive fighting style.
When he fought like Machida, against Machida, for 5 rounds he didn't gas and actually looked fresher than Machida did. So I do believe that Shogun trains hard and is in good shape, it's just that he throws 100 percent power shots that drain his energy quickly.
In the first fight Rogerio had the upper hand early, and dropped Shogun with a hook (I'm thinking a right hook) but Shogun came back and outlasted Rogerio. He won the decision mainly from Rogerio's guard, as it's pretty difficult to beat him any other way. One of the best fights ever as I remember it