After I downloaded this tool, I did give it a try,
I picked five non-Hunting Leaders and the tool gave me:
Qin Shi Huang
Louis XIV
Mao Zedong
Suleiman
Mehmed II
2x Chinese & 2x Ottoman.
Could you change it, maybe first selecting Civs and then selecting the Leader.
I can re-run, no problem. But then the changes of having America in is 3x times of getting Arabia in. The game choose first the Civs and then the Leaders