I actually don’t want the game to warn me if I’m about to break my oath, though, as I’d feel that would cheapen and gamify my paladin’s decision making. But I would like (a) the basic tenets of each oath to be clear in the game, (b) oathbreaking to make sense in light of those tenets, (c) the ability somehow to argue after the event if I don’t agree that the action broke my oath.
No matter how clearly laid out you think your tenets are, there will always be ambiguity and oathbreaking will always seem arbitrary. In the "old days" of D&D there wouldn't have been any question as to whether or not killing goblins was "good". No paladin would lose his god's favour for killing them, irrespective of who attacked first. I am very sure that you couldn't come up with a list for any of the gods that wasn't plagued by subjective interpretation. And I bet that interpretation even changes depending on the age, background and political orientation of the player. If you wanted some post-hoc justification system, Larian would have to anticipate every one of these interpretations and make a judgement on them, which will then just piss off players more. The only clear system is one that tells you of each oathbreaking action in advance.
