Yah, its a good win. Regardless of Nog being passed his prime he's still the second best hW of all time and submitted a high level BB like that is impressive. And Nog was still relevant a top HW in 2011, he was ranked top 5. Same with Cain, and no he was not broken lol.
Again, you don't seem to understand how the sport works and have a grasp on reality. Let me explain to you again.....there are no fighters that consistently fight and win over nothing but elite comp, in their prime with no faults. Every fighter that has a impressive win streak is going to have a mix of wins where you can find faults of injuries, out of prime fighters, lower ranked fighters etc. That's why your thought process and criticism of Stipe is very amateurish.
Even the best win streak in say Jon Jones and his 8 defenses and title win. Well all you hear is Vitor, Chael and Machida are MWs, Shogun and Rampage were beyond their prime, he should have lost to Gus. You can do the same with Anderson.....Leitas, Maia, Nate, Okami , Lutter and Cote were not elite and good to mediocre fighters, Vitor was coming of a two year lay off etc. You see what I am getting at?
You have this standard in mind that a fighter needs to beat nothing but elite competition, in their prime, injury free, on a big win streak etc to be impressive. It doesn't exist buddy! The fact that guys like Anderson, Jones, Fedor, and Stipe are doing what they're doing and really only a select few can do it is very impressive.