So that's why she always argues with Cullen AGAINST Templars, good to know.
And then she meets the mages.
Templars need more people like her on their side. And its so obvious and blatant that I think you muted the volume and closed your eyes to miss it.
Suggest meeting Fiona after Val Royeaux, Cassandra express a need to consider the Templars. Suggest meeting the Templars, Cassandra agrees. Someone obviously wasn't paying attention.
The minute you are all gathered in the room for the first time she says we immediately need the mages and argues with Cullen about how Templars can't do it. She simply doesn't believe Templars can help with the breach and its a logical view. We have no instance of Templars closing any breach but mages have closed them in the past. She only starts to "prefer" Templars once you side with them.
And then she meets "Fiona" and all that goes down the drain. When she meets Fiona in Redcliffe she's completely sure then that the mages are simply trying to gain the favor they lost back. That with her constant insulting of them should make it obvious who she prefers, even when you discount approval. It's not that hard really.