He was friends with an pretty ruthless warmonger, and didn't seem too concerned about his methods. I'm not so sure about that...
If by "ruthless warmonger" you mean "Guy who spent his entire adult life fighting the Second Blight, going to far as to save the bacon of the Grey Wardens when Tevinter abandoned them to their fate" then sure 
Me, I think it's quite remarkable that Ameridan, a Dalish mage, was not only the last Inquisitor, but the first Lord Seeker of the Chantry, and best buds with Cordillus Drakon, the man who was the architect of the Chantry and the Nevarran Accords, which set up the Circle system. If those two could have worked together so closely, what might the Chantry and the Dalish have become?
It really makes you think of what could have been, of paths not taken.