I don't collect any cards because the player is a HoFer. I collect in a half dozen different foci and collect HoFers along with everybody else in the focus. For example, pre-war Washington Senators (Nationals, etc.) which includes a fair number of HoFers: Griffith, Johnson, Rice, Harris, Goslin, Cronin, Manush (with cameo appearances by Mack, Coveleski, Speaker, and a few others). But post-war Senators is a HoF wasteland: Killebrew in '55-60, Herzog in '57-58, Williams as manager '69-71. Then there's first black players which is rich in HoFers: Ernie, Campy, Doby, Monte, Minnie, Frank, and Jackie (out of 19 players total). So, answering your percentage question is difficult.
My only Speaker:
https://www.net54baseball.com/attach...1&d=1688145604