Only one of those people is a companion though, which was OP's point. In all 3 games the Mage companions have generally been the ones to have something big about them.
I'm gonna squint at the mages in the next game like a Templar.
Well.. Alistair (son of a king), Isabela (about the relic), Sten (Says no to everything), Zevran (He tries to kill you), Blackwall (Good lair), Iron Bull (A giant spy)
Everyone have big things.
I know you are talking about how all mages blow up the world, or part of it (Jowan pls) but is because the magic isn't easy. Like the kings who have too much power and destroy his own kingdom, but mages like Wynne... possessed by a spirit...
Velanna
... who is aggressive and kills humans.. 
or.. Irving (?... Who doesn't care for the apprentices...
Merrill 

Oh.. well...
There must be a mage who does something good, no?