The Wise Guys, or as they are referred to in their native dialect, "Vice Gice," are the aristocratic class of Souschefistan.
It is believed the phrase "So you're a wise guy, eh?" is derived from this group of individuals.
Each family in the aristocracy has a letter designation.
So it is likely that the phrase was spawned by an unwitting member of the proletariat referring to one of their betters as "So you're a Wise Guy A?"
That, or the phrase is a result of a Canadian visiting Souschefistan.