Well, I didn't say that immunity is bad, and it's not just about good... there's bloodlust, prayer, accuracy, magic resistance (they're not only used for their direct purpose but also to increase priority), executioner, or frenzy, and so on. They can be applied depending on what magic you have, etc.
Troop morale: +1 if there are archangels (angels too) in the group;
+1 if the troops share the same alignment.

Added 3 minutes later

Be clearer, it's unclear what you meant when you said "an archangel has a chance to move twice without taking damage," can a dragon do the same?

I didn't say it couldn't - I just said that a dragon has a morale of 1, and an archangel has a morale of 2, which means that, in theory, on a given turn, the archangel can move twice and, assuming the opponent is a dragon, attack it twice in one turn, taking damage only once.
A dragon also has this possibility, but less often.

Added 4 minutes later

Are you just trying to joke? If you're talking about an archangel and a black dragon, then why give the archangel "good," it won't do anything :D.

You're wrong - it will give an even greater turn priority :D, and I wasn't necessarily talking about an archangel and a black dragon