For example, in the Champion of Just quest, we see some of the people in the Templar order are marksman. Thus I never understood why Templar wasn't a specialization for Archers either.
And considering if, say you play a Trevelan Inquisitor, the family goal for the Trevelan is for them to become a Templar.
Magic specializations I can understand the restriction, but some of the specializations I feel shouldn't have been class restricted.
Good point. Most of them shouldn't be, now that I think about it.
Templars have all manner of fighting styles (except mages, of course), so any rogue should be able to be a Templar too, like you said.
Reavers were all three classes in DA:O, even if it was still only available for warriors like DA:I.
Tempest: There is no reason a warrior or mage couldn't be one, though it might be a but redundant for a mage.
Artificer: Anyone can make traps.
I can see Champion or Assassin not necessarily melding across classes, but the rest definitely should be able to. But only magic specs really couldn't work.
Why did you bring this up? Now it irks me! 