They do overdo it compared to what is realistic, but also...

People are actually reasonable if they aren't taking things, within their own narrow logic. A really diplomatic person can actually find themselves creating common ground with people a lot.

The Warrior of Light is meant to be the best diplomat in the universe, getting warring nations to become allies and develop trade relationships with eachother. It happens with the dragons. Then in the First, unifying everyone to work together after being conquered. And well it always happens. We put a lot of focus on the fighting ability of the Warrior of Light, but a big part of it we don't talk about is how extraordinarily diplomatic their silence and mannerisms (nods and dances) is.