Is 59.1% passing against minor-league ("college") competition actually good?
The league average in the NFL, against NFL defenses, has been over 60% since 2007 and over 63% since 2015 (except for 2017, when it fell to 62%). This season, it's 64.5% so far.
And now Hartman's going to take a sixth year in minor-league ("college") football in 2023 at age 24. That means he'd be over 25 before taking the field for an NFL team in 2024. Yikes.
Phil Haynes, who's been in the NFL for four seasons, was Hartman's teammate in 2018. Haynes will have completed five seasons before Hartman could even enter the draft.
Part of the advantage of drafting QBs is that they're still on the steeper part of the aging curve, when you can reasonably expect their ability to grow in big steps year-to-year. Hartman would start his career at age 25, already in the early peak years when the curve tends to start growing more slowly.
I won't go so far as to say "not a prospect," but I feel pretty comfortable saying "not a top prospect." And Hartman and those advising him must agree, or he'd be entering the NFL draft this season instead of screwing around with changing minor-league teams (moving up from high-A or AA to AAA) and risking major injury before getting an NFL payday.