Jake Haener
Eventually we’ll get an opportunity to look at two similar throws between Haener and Carr to see the difference in the time between the QB’s hands breaking from the ball and the ball reaching the target. The closest one I could find from yesterday was around a 25 yard throw for both, with Haener getting there a quarter second late. That amount seems trivial, but people fawn over players that might have a 40 time that is less than a tenth of a second faster than another player at the same position.
Also, I remember a great interview with Roman Harper where he discussed that one false step playing defense in the NFL can be the difference between 4th down and a touchdown. The margin for error is so small. The same goes if the ball hangs in the air to allow extra step(s) for the defense to make a play.
You're making the case that Carr has a stronger arm than Haener, which I don't think anybody disagrees with. For that matter, arm strength is on a spectrum and not really a strong / weak binary.
I've posted an article before in which the author does a good job of analyzing the arm talent of the QBs in the 2020 draft. I've posted it a couple of times that I remember, so I'll just link back to the more
recent post rather than sharing another direct link to the article. (It now requires a free account to read but I think it's something you might actually enjoy, given your interest in data-analysis.)
He actually discusses and analyzes the relationship between throwing variables and margin of error, so I think you'll appreciate that.
Anyway, if arm strength was the only factor in determining a QBs success, I would agree with you, but we already know it isn't. Brees never had heralded arm strength but he made up for that with elite pocket awareness, mechanics, and decision making. If Haener is to be successful, he will have to hone a similar skillset, and fortunately, there are some indications he possesses the raw skills to build on.
I'm more worried about his size than his arm talent and I certainly don't think he's anything close to a sure thing, but if he doesn't pan out, I don't think it will be because he doesn't possess enough arm strength.