All oaths function the same - i.e. the narrative will insist on them being
completed in some form.
The dead blokes didn't make a bad oath, they made a good one. Their error was
expecting to get away with breaking it without any consequences. And they did
eventually fulfil it.
Galadriel knew that if she made the oath she wouldn't be able to change her
mind later. Some of the less gruesome of Feanor's son's found this out too
late. Again, the oath will just function as an oath must. It's just like a
technical form. It's what you choose to do with it that counts.
Surely you can make an argument that is
qualified?