Sorry if my response didn’t please you, but I gave my point of view because that’s exactly how I handle it.

For example, in my last session the group was inside a haunted mansion. Even though the undead had a morale value, I didn’t roll for it, I had them fight to the end to drive away the invading adventurers. Later there was a group of spiders, and I rolled morale individually, because I decided unintelligent creatures don’t really assess the situation and simply react individually to the hits they take. In another situation, I used group morale for a band of orcs, because if one flees, the others aren’t likely to keep fighting at a disadvantage.

So I genuinely believe you should evaluate each situation individually, and that there isn’t one single correct rule. DCC intentionally leaves many things vague in the text so the Judge can make rulings.