Helton handled JG with low risk/low reward play calling so of course his accuracy looked better.
7.8 yards per attempt vs 8.4 yards per attempt
Also not sure what 9 games you're talking about...Georgia was Maurer's game so JG only had 5 attempts. Mississippi State was also supposed to be Maurer's game, so he only had 7 attempts hit on 6 for 106 and a TD though. Kentucky again was supposed to be Maurer's game so he only got 8 attempts and hit on 7 for 115 and 2 TDs.
Chattanooga he was 7/8 for 142 and 3 TDs
I actually thought Georgia State was a good outing for JG, his BYU game was the worse one. His best performance other than Missouri was probably South Carolina, 11/19 for 229 and 2 TDs before being knocked out of the game. But despite missing series in 7 out of 14 games he still managed 5 games with 20 or more attempts compared to 7 in 2018 where he only missed real snaps in 2 games.