Not sure that I follow you, William.

Quote:
But 2 to 6 staves is minimal indeed for a full orchestral piece.


The "short score" is customarily used to create the "long score" and can contain all the information for the long score. Rozsa was speaking of short score as opposed to a sketch, which is really brief.


Quote:
He may say 'violins' but how many for a particular passage?


Surely a trivial objection. All of the different violin parts will be indicated, and the number of playing each depends on the budget.


Quote:
If you dig out his orchestral long scores, he uses more staves than that.


In the long score there are indeed more staves (one for each different instrumental line), but the information can be completely indicated in a short score. Perhaps you are referring to cases where Rozsa wrote the long score himself without an intermediary short score? Herrmann did this, according to legend.