Quite the opposite actually, all of said subsidiaries were established recently. You actually missed another one, called Jetz
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Photo © Andy Vanderheyden
Here is an oversimplified summary:
Jazz: A brand merger of AC
's regional airlines (former Air Ontario, Air BC
etc) into a single entity. Jazz employees are separate from AC
Mainline, and there are specific rules on what type of aircraft they are allowed to fly.
trying to curtail WestJet's growing dominance in Western Canada by throwing the same idea back at them. It is a low cost, no frills operation with some staff separation from AC
mainline, an has replaced some of the AC
Mainline flights. Right now though, it isn't expanding as quickly as initially hoped.
Tango: Low fare, low frills division that has been phased out of its own separate fleet. Instead, now Tango fares are offered on AC
Mainline flights. This in my opinion was the best idea AC
has come up with in a long time.
Jetz: Has a small fleet of A320s, previously 737-200s. They are configured in an all-business class seating layout and specialize in corporate and sports team charters.
With the merging of Tango's fleet back into AC
mainline, there really aren't any glaring inefficiencies between the subsidiary companies.