Jake Haener

Reviews of his arm strength run the gamut but from what I've seen, the consensus is that it's average to above average. One report called it "intriguing" because he "flashes good velocity" but then they still questioned his arm strength. From what I've pieced together, there's the opinion that he loses a lot when he's not throwing from a set base.
That last sentence is key, and I think its what NFL scouts are really looking at when they talk about arm strength. Can the QB still sling it when they don’t have a perfect throwing base? I think anyone getting drafted can likely put some heat on it with their best form.

Carr can, in my view, throw it significantly further and faster than Haener without needing that extra step in the windup, and without that perfect base. The same goes for peak Brees, he could let it rip at a faster speed than some remember without having to load up. His throwing motion is probably my favorite among NFL QB’s, but of course I’m biased.

Worth considering also, that two QB’s may be able to achieve the same speeds, but the one throwing with less effort will probably be more accurate because they aren’t having to use all their strength to push the ball.