The equivalent of National Emerald Executive level would be President’s Circle at Hertz. Odds are you won’t find anything great outside of a paid upgrade unless you are PC status with Hertz.

Vegas can bit hit or miss in terms of selection at least for Hertz. Out of 5 recent rentals there with Hertz we got a Mustang GT Convertible once (which was a blast) but the other 4 times were nothing to write home about. National seems to have a better selection overall in our experience so while you might get lucky at Hertz, you’re probably going to be better off on the whole renting from National as an EE there.