Agreed. BUT they are never considered upper tier Jews. By that I mean the rabbinical class who are allowed to rule other Jews. Those must be Jews on both sides and must be from certain families (Cohen, Kahana, kogen, rabin, rabinovich, rubin, etc..). Family names such Rubin/Rabin are derived from Rabbi. Same as Cohen/Kahana/Kugen which are from Kahen which means priest.