this form of sportscaster speech:
"your william shakespeares, your joan of arcs, your secretariats"
drives me insane.
the person who uses this construction
is trying to take an extraordinary person,
primarily famed for their utter singularity,
and speak as if there were bunches of them.
or
("a william shakespeare, a joan of arc, a secretariat")
as if they represented a general category teeming with stand-ins.