Do you even watch football? Watching both of them their rookie years, there's no comparison. Peyton had a rookie season that was better than most seasons that any Bears QB ever had even with 28 INTs.
Justin Fields is a low bar. QBs in their rookie that have had better success than him statistically? Matt Ryan, Justin Herbert, Dak Prescott, Ben Rothlisberger, RGIII, CJ Stroud, Cam Newton, Kyler Murray, Russell Wilson, Baker Mayfield, Andrew Luck, and those are just the good ones off the top of my head. I'm sure there's plenty a tier or 2 lower that had better ones as well.