When I watch Leonard vs Hagler, I see two atg fighter's that have clearly lost a step. I hear what you are saying about Norris and I agree that he was a guy that would neglect his defensive responsibilities which would normally spell trouble against Hagler. Hagler just didn't look great against Leonard and I believe had they fought five years earlier, Hagler would have destroyed Leonard. I still think Hagler beat Leonard but both guys were definitely past it. To my point, post Hagler, Leonard never beat a great fighter again. He beat a one handed Donny Lalonde and really lost to Hearns.
Terry Norris is the type of guy whom I fell in love with when I first started following the sport. Truly I thought he was one of the best ever. All these years later as a seasoned fan, I realize he wasn't great at all. He fits into the "very good" category rather than the great. 75% of his reputation is based on the Leonard performance. Anyone with a brain knows that the Leonard of 10 years earlier would have destroyed Norris. The Curry of 84-85 also would have smashed him.
I agree that Leonard and Curry were better prime for prime. The biggest issue with Norris was his inconsistencies. He would often neglect defensive responsibilities and get caught with stupid **** or get DQ for stupid fouls. Later on, he clearly was suffering from CTE and lost to fighters that he would have destroyed earlier. You are correct that he was not a great fighter overall even though he is one of the most talented/gifted guys I have ever seen. He just simply was not a complete fighter and was clearly not on the level of a prime Leonard or Hagler.