Because of the size disparity Miocic and Maldonado is pretty close to being unethical, especially considering one is a ranked heavyweight and the other is maybe a top 20 light heavyweight at best. Patrick Cummins is a legit, able bodied fighter with a background as a world class wrestler, who came in a short notice to fight somebody his own size. It was a mismatch because DC is special, but not unethical. Cody McKenzie and Chad Mendes was a huge mismatch that never should have happened, but I wouldn't say that was unethical either. On the smaller circuits you see these things happen, like fighters like Jon Jones or Travis Browne we coming up and smashing people in just a few seconds. Sometimes special athletes make mismatches out of almost everybody, it's hard to measure it all, since the sport is unpredictable. The best you can do is just not throw people into fights were there is a huge disparity in size, and competitive experience.