In point of fact there were FOUR Ferengi in "The Last Outpost" and the first one seen is Daimon Tarr via the viewer, played by Mike Gomez. As such Shimmerman isn't the first Ferengi the audience sees.
What would "the original Ferengi" mean to an actor? Not the first one the audience sees on screen -- it would be the first one in rehearsal or the first one with a significant role.
Who cares? The Ferengi back then were just annoying and creepy. Quark is the first Ferengi with dimensions, even endearing qualities at times.
Well, there was that scientist that seemed sympathetic but he wasn't as complex a character as Quark.