You ommited the other glaring wart from the games you isolated, fumbles.
9 games, A dozen fumbles, 8 lost. One lost per game.
For comparison, hurts has 7 lost fumbles in 26 games with your 29 attempt benchmark. Less than one every 3 games.
Allen has 21 out of 60..a touch over 1 every 3 games.
Tua has 6 in 29 games, almost one every 5 games.
Jackson has 8 out of 31.
Herbert has 6 out of 57.
His penchant for fumbling also factors in to the play calling and results.
I watched years of cherry picking numbers and stats for grossman and cutty, overlooking the glaring faults that never went away.
Parsing his stats like you have in your post to 9 games out of 3 years with his best possible performance against the worst possible opponents results in 2 turnovers per game.
He has fumbled 35 times in 35 games, he has 27 interceptions.
His production on the good side of things is pitiful in comparison.
36 passing touchdowns in 35 games, plus 11 rushing.
Compare that to hurts, a decent qb that fumbles more than average... he has 36 fumbles with 10 lost with 37 rushing touchdowns.
His fumbling is a lot more than you would like to see, but at least each fumble is offset by a td.
Bottom line is fields' net passing production is that of a low level game manager, but he doesn't have the positives of a game manager, namely the lack of turnovers.
9 of 35 starts have been turnover free, and of those 9 games, 2 had 6 completions or less.
The record of those games were 2-7.
That is non functional.
Fumbles are primarily a byproduct of sacks, and as his sack % goes down, the fumbles metric will follow. Getting his sack % down to the sub-8% range should be the goal for the rest of this season and the next. That's both on Fields to improve his feel and timing, and on the team to add another go-to besides Moore and improve the pass pro.
In general, it’s not like he has abnormally bad ball security when getting hit - when you look at fumbles as a percentage of sacks + rush attempts (aka only two times a QB can fumble), he’s in the middle of the pack of other QBs, and has also improved significantly each season:
Overall first 3 seasons - 8.2%
Rookie - 11.1%
2nd year - 7.4%
3rd year - 6.6%
Other active QBs (Initially started breaking down by the starts of their careers where fumbles may be considered an issue to give a more direct comparison, but that was too much work, so unless noted, that’s their career %):
Jackson - first 3 years - 5.6%
Hurts - first 3 years - 6.1%
Herbert - 6.1%
Watson - 6.2%
Burrow - 6.6%
Murray - 6.7%
Wilson - first 8 years - 7.0%
Mahomes - 7.1%
Allen - first 5 years - 7.5%
Rodgers - first 10 years - 7.9%
Stafford - 9.1%
Dak - first 6 years - 9.9%
Mayfield - 10.0%
Lawrence - 10.7%
Tua - 12.6%
Carr - 14.5%
So even with two of the MVP candidates this year in Dak and Tua, defenses know if they can get a hit on them they have a 1/10 chance or better of jarring the ball loose. So Dallas went out and surrounded Dak with five 1st rounders on offense (3 of them OL, 2 WR), and Miami probably has the best WR duo in the league and an offensive coach that know how to make defenses pay.
Also compared to recent famous statue QBs' fumble % just to show how much of a sack-driven metric it is:
Matt Ryan - 10.4%
Tom Brady - 10.7%
Ben Roth - 10.8%
Drew Brees - 12.1%
Philip Rivers - 13.1%
Peyton Manning - 13.2%
Eli Manning - 17.2%
I don't think anyone is happy with the amount of sacks currently being taken in this offense, but it's not like he's regressed or the league has adjusted to him like Mac Jones or Kenny Pickett, but rather has shown steady improvement in most of these metrics that correlate with each other and trend toward successful development.