Stroud is averaging 291.8 yards a game which puts him just in front of Cousins (291.4) and Tua (289.9).
This pace would put him at 4961 yards for the season which would shatter Luck’s record of 4374 (273 yards a game)–in fact at Stroud’s pace he’d break it after 15 games.
Plus Stroud has a rating of 101, while Luck finished at 76.5.
I’m glad you added the part about Stroud potentially breaking the record in 15 games, since it accounts for the extra game