Not sure of the history of the Thrower's 10,
But the 1st guy I remember (after Koufax, Marshall and Jobe) that taught and showed us arm dumbell exercises for the baseball player was Mark Davis, with the Phillies.
And, who became a NL Cy Young Award winner in 1989 (and with 44 saves for the Padres).
Davis also pitched 18 years in the bigs.
His approach was 7 vital arm exercises and remain
in use today.