My female elf Inquisitor sided with the templars as a Dalish Rogue, and choose to ally with them. My previous Qunari mage choose to side with them, and ally with them.
When you think about the skill sets of each, Templars would always realistically be the way to go. You have a choice between a group of volatile persons who are losing a war they started, succeptable to possession, and are actively fighting a group that can nullify their abilites through lyrium consumption, or the group that had church backing and money flowing into it before the split, access to all the drugs needed to fuel their powers and habits, rank-file-and order, and combat experience to a degree (more so than mages).
Headcannon is nice, but reality is nicer. That, and the mages ****** me off to a extreme degree in their logic, per Fiona at least. While you don't ever see Rhys or Evaline in game, you do meet the Ex-Warden Elf-Punk that is Fiona the Enchantress. Because after all logically, after declaring independence just to stick it to the man let's indenture ourselves to a magic empire. It's not even close to as bad as it was under the chantry! Now we're actually slaves!
My headcannon works in that the tower is restored. If I save the mages, it's making them allies for time being, then restore the tower. If you're Dalish, at least for me, the headcannon is: God damn it Anders, god damn it Lambert, let's just reset and talk with the new, reasonable divine while the lead Seeker isn't a sick S.O.B.
Although, with that headcannon, I would like to mention that Viviennes viewpoints on this, while being extremely pragmatic are as much insufferable.