I've never considered this, but you just gave me a thought. In a world like the Forgotten Realms, where powerful casters are a dime a dozen, the only reason why there is a royal succession at all must be that whoever succeds a king is not willing to dole out the cash to have the king resurrected. Which has certain implications on who is most likely to actually inherit in the long run...
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Anyway, on topic:
Dies Horribly's story is nowhere near over. If we go by a classic three-act story, he just finished the second act: he faced his main antagonist (Junior) for the first time; he was defeated and lost a friend (Klik). His arm was lost (again) and replaced with a new one that we know can be used as a weapon against Junior. What's missing is the third act, where Dies becomes proactive, goes to fight the villain of his story and triumphs.
As for Cheif, I never considered his story to be over. He had barely begun showing courage and atoning for his previous cowardice. The whole Brassmoon arc was mostly just him trying to survive; he never showed real heroism, as opposed to the other goblins. He never really faced any of his demons (not his cowardice nor his unwillingness to be chief). Also, he was the only one who noticed that Saral Caine wore a belt that looked like his crown; a plot point that never went anywhere (yet, at least). There was a lot going on that was just cut off when he died. Note that killing Chief, especially in a heroic sacrifice, is a fitting end to his arc, but he would have needed an arc to begin with. Just as an example: imagine Chief confessing to hiding while the goblins he was supposed to lead were dying. Imagine him and Complains having a falling-out over this. Then Chief sacrifices himself and marks Complains as the future chief before dying in his arms. Suddenly, that scene is so much more meaningful; it's chief, in his death, saying "you were right and I was wrong." But this would have required more time to actually establish a full arc for Chief.
To this day, I believe Chief died purely for meta reasons; Elli wanted no clerics in the current dungeon, as they would have trivialized the lol pearl trap. She wanted Complains to be chief and Fumbles to be teller and neither would have worked with Chief still around, so she needed to get rid of him.