Given that we have enough examples in real-life about people using events from hundreds of years in the past to give sense to or justify current traditions, politics, territorial claims, religious strife, etc. (rarely the elephant in the room is mentioned when talking about elves in DA), I see it as another example of a typical fantasy trope: using a fictional group to showcase a real human trait.
Bad time to point out I think hundred-year-old-grudges and revaunchism are sad and pathetic and harmful in the real world as well?
I don't find it unnatural or absurd. Just contemptable.
That's... pretty reductionist. First, a nomadic tribe based on oral traditions is going to have much less that settled kingdoms. And the oldest the tradition, the more respect is going to have. You know, like the Iliad and the Odyssey. Not many things survived from the Greek Dark Ages either. Not to talk about a group scattered all over the continent, whose scale is going to be much smaller.
I don't consider that a strong argument for what I'm trying to get at. I am one of the frequent reminders that the Dalish have an oral tradition- but I think this is one of their problems. Especially for people with a history fixation. Oral tradition is useful for some things but far from reliable, and writing is far from unknown to the Dalish.
The Dalish should be writing things down as fast and as much as possible, to not only keep regained lore recovered but to also build and develope their own history. The Dalish should know who their leaders are and were. The Dalish should make records. The Dalish should write down the old lore, oral and newly found, so that it doesn't get perverted or lost or misremembered when it's just oral tradition once again.
Would it be hard? Certainly. Would it be impossible? Far from it.
For example, in the Dalish Origin in DA:O, the player could hear from craftsman Ilen the story of how they banded and defeated the Clayne, ensuring that the Dalish clans could roam those spaces in safety. There you have a historical event far later than the fall of the Dales, about a mayor conflict between Dalish and humans, which had effects in the present day, and that the Dalish remember with pride. Of course, it hasn't the same scope as an Exalted March, but it would be like making fun of any small country's history just because they're small.
That... struggles to be called a major conflict, unless we write down 'major' to be 'inter-tribal.' And there's also the previously noted historical disreprency within it- Ilen's mention of his father's involvement, while dating it to the aftermath of the Dales. Which, going by the lore and word of god, both couldn't be true since Dalish don't have that sort of lifespan except in the most unique questions.
But it isn't a bad question. The Dalish could have more (Gisharel was their Genitivi back in the day, he could have spent more time recording other events, couldn't he?). Hell, the Emerald Graves proved that at least the Dales had it. They had tree-tombs to remember their people's great deeds, from warriors and leaders to researchers and scholars.
Arlathan had written records, and the Dales certainly did. The Dalish also have all sorts of places to hide their written histories, and can make contact within human societies to help produce such records.
Ah, but that's a false comparison. Our own sense of history means nothing because our society is much different from Thedas. A better example would be asking a person in the Middle Ages about those events; even better, ask a member of a nomadic tribe. However, then we might find out that they wouldn't be in a better position than the Dalish. As I mentioned before, Homer and Hesiod didn't sing the praises of their current societies, did they?
...the people in the Middle Ages also had a plethora of major events of regional and occasionally world-influencing natures. Plagues, Crusades, invasions, civil wars, religious wars. Just because the scale was smaller than our own contemporary examples (Arab Spring, Cold War, WW1, etc.) doesn't mean that the Middle Ages was empty of events.
Nomadic people of oral tradition might not remember them... but that's the weakness of an oral tradition rather than written history.