What if the lead aircraft (if there was one...) had mentioned to the
controller that they were a "flight of five" from the Pan Am Academy?
Might
that have made a lightbulb go off in the controllers head that "these five
probably have similar call signs." ??

The only reason I ask is that we have a lot of Embry Riddle planes in AZ
and
they all end in ER which I could see causing a similar set of
circumstances...

Not that the contorollers didn't contribute to the accident, but wouldn't
the PILOT be thinking 'hmmm, was that call for me?' If I were flying in
mountainous terrain and was asked to descend below safe altitude, I sure as
hell would stay right where I was until I found out what the controller had
in mind.

There is a magic word you can use when a controller asks you to do something
you feel is unsafe. 'Unable'.