Of course, you also shouldn't just frame everything that way, otherwise they won't understand the reasons they should want to do things, and because if it is a "want", that should be weighed up against what other people want and how important it is to them, fairness, etc... which is probably a more complex problem than most.
With that you don’t need a hierarchy:
1 and 2 are the same, you just have shallower arguments in 2
3 is not an option IMO, it really should be 2: you can plainly say “I can’t explain, but that’s what I believe is right” and let the kid decide what they want to do.
This helps if the kid doesn’t take your side: if you’re not happy with outcome, there was clear a warning, making an eventual punishment more fair;
Or if they happen to be right, you don’t lose credibility as you were transparent about your standpoint and you can make it right to them.
Wandering the topic a bit, I'm reminded of a book [0] which argues that sometimes "because that's what I want" is actually better and more-honest than making up a reason like "because that's what good little children do."
So I'd like to propose a hierarchy of
1. Explain what practical or empathetic concern drives you to make the request, so they can learn to emulate your logic.
2. Ask them to do it because you desire it.
3. Explain with a "you should always" story that involves badness or guilt which isn't actually the logic you used to reach that decision.
[0] "When I Say No, I Feel Guilty" by Manuel J. Smith