Your last sentence sums up the problem: there should be no research period. We're not researching who is a Polish Jew or a British Jew, but rather finding external references that can attribute both qualifications to a person. Those that don't qualify either "Polish" or "Jewish" don't belong on this list. But I'd like to point out that by your personal definition of Polish Jew, it would require that the person is "raised in the customs of traditions of Polish Judaism?" Since you believe this to be the criteria, why did you revert to include actress Scarlett Johansson and Adrien Brody? You have an external reference that qualifies that these two were "raised in the custom of and traditions of Polish Judaism"? You see there are problems with such personal interpretations of what it is to be a Polish Jew. This is why there should be no argument over inclusion, as there isn't one on the others in the series of Lists of Jews by Country.