You just completely ignored the actual data and went with your own unsupported evaluation of the player. Are you Stan? That seems to be how he operates.
He didn't give some unsupported evaluation, he laid out the range in which Klingberg could effect this roster. Worst case he is nothing, best case he helps us. How is that unsupported or even in question?
We all see your "data". There is nuance to these things though. The year he fell off, is around the same time Heiskenan came in and took over, they didn't play together a lot. Those stars teams were deep with good defensive players but not so much offensive guys for someone like Kling to work with if he wasn't getting the minutes with Benn/Seguin. Lots of 40pt guys but not much more than that.
Then you have covid, which I think should be a year that has an asterisk next to it for nearly everyone considering the format the league took.
Next comes his contract year, he produced well but was seemingly a pylon in the d-zone. Not the first guy to have a bad contract year, and wouldn't be the first to rebound after one.
I think we can all agree that his stats on the Ducks have an asterisk. Many thought Fowler was washed from his time there, and he looks great in STL. Kling had great numbers with Minny that year.
Then TO, where he got 14 games before going down for this surgery. That doesn't help you evaluate how he could perform here, at all.
What I'm trying to say is there may be reasons for his stats to fall off a bit before he went down for the injury. We also don't know how long this had been effecting his play. This is a guy that ended up losing out on millions, and who knows this is his last chance to claw some of that back. Give me someone who has that level of hunger driving them, with a history of elite play, and I will bet on them every time, especially when the bet is essentially free.