I don't know if using QBR and passer rating is the best way of analyzing a quarterback whose receivers dropped passes at the rate ours did. Both rely way too heavily (imo) on completions and comp%
Nor is gross yards a great metric for QB performance. ANY/A, a very good QB metric, has him at 23rd overall which is where I'd put him comfortably without factoring in what he gives you on the ground.