Are you sure you have your plane a pilot correct? Erich Hartmann spent most of his time shooting down Russian planes. He said the Il-2 was heavily armoured and difficult to shoot down but I don't remember him engaging P-47's although he did engage a few P-51's.
I read it in an assessment by him of various aircraft. No, it is my understanding that he didn’t shoot down any confirmed P-47s but I think there was one perhaps. He did indeed spend most of his time on the eastern front. He tried, but didn’t manage to take out a P-47. The wing spars on that were quite stout, and the plane flew off after he engaged it.
When comparing “kill” totals, one must keep in mind that national standards were different.