No, not absolute. The pilot is the most important factor, but it'd be foolish to think a P-40B is as good as a P-47N, a Bf109E-4 as good as an Me262, a Hurricane Mk I as good as a Tempest Mk V, a Ki-43-Ia as good as a Ki-84-Ib or an I-16-18 as good as an La-7. Certainly all ten of those fighters can kill and be a threat in the hands of a skilled pilot, but nobody reasonable is going to agree that, with skilled pilots, the five from the beginning of the war are as capable as the five from the end of the war.