I don't claim to be the biggest NBA fan or an expert, however, my eye test tells me that he was part of a great system and not a top 5 player in the league. He was a big part of the championship team, but he had lots of help. You seem to be most hung up on the Rose comparison. Throw that out if you want. I think they both rely far too much on pure athleticism, but we can agree to disagree. I did say from the start he is a sold defender. I openly admit when I am wrong. I have been wrong many times and I could be again, but in my opinion he isn't among the best of the best. If he goes on to sign with the Lakers or not, I still maintain that we will see a decline in his numbers. One thing that I won't change my opinion is that he isn't a good teammate. Even if he did sit out while being cleared, he should have been part of his team and help cheer them on. Without going back and looking it up, I think Rose was with his team when he was "injured".
He wasn't just a big part, he was the MVP of a championship team, one that the rest of his teammates acknowledged was the best player on that team after that finals.
His athleticism allows him to have a high ceiling as a player, but frankly it's the least impressive part of his game. He's almost always in the correct position, almost always makes the correct read on when to help on defense, almost always makes the correct pass, rarely takes a bad shot, etc. He's one of the smartest players in the league.
He's also more than a solid defender, he's the best defender in the league. Nearly all advanced stats in the NBA are imperfect due to how dynamic of a game it is, you have to weigh them all together to get a great picture of where a player should be ranked. In these, from Leonard's last healthy season, the offensive measure is biased towards primary ball handlers & centers who mainly shoot from close range, & the defensive measure is biased towards centers who protect the rim & grab rebounds which end other team's possessions, & Leonard still comes up aces.
Leonard's injury was misdiagnosed by the Spurs' team doctor, he went to another doctor who handles several sports teams who said he was still injured & wouldn't clear him. While out the Spurs' GM, coach, & several players called him out & insulted him. I can understand why he wasn't feeling the love & would've rather received treatment from the doctor that diagnosed him correctly instead of being in San Antonio being treated by the doctor that got it wrong. That team still wants to mend fences & sign him to a $200 million dollar contract. I think they know what they have & how good of a teammate he is