Look who he has throwing him the ball for crying out loud. Chris Givens is an excellent receiver, too, yet he hasn't done anything all year because Sam Bradford is/was Sam Bradford. Same with Dwayne Bowe.
I'm sure Wallace "opens things up" -- in fact you can see it on the all 22 look at times -- but the plan still relies on Hartline and/or Gibson beating man to man coverage, which they don't do consistently. They're okay players, but not man to man beaters. The offensive line struggles is also going to allow teams to creep up more on their coverages. Can't throw it to Wallace deep if you don't have time.
Jennings also would have not allowed Ireland to feel safe and pass on the position again in the draft. Like I said at the time, he just thought everyone needed a demotion. Wrong.