I'm unsure I follow your "modeling as a cow" analogy. Usually, that's used to show the model does not adequately reflect reality. But that doesn't hold in tort cases. Compensatory damages are the majority, by a considerable margin. According to DOJ data[1]:

- Punitive damages were awarded in only 5% of trials where the plaintiff won

- It was lower for tort cases (3%) and higher for contract cases (8%)

- It is lower in product liability and medical cases (1% each)

Those findings show that the punitive damages awarded are both relatively rare and modest. A "spherical cow model" based on compensatory damages is probably still a very good model.

[1] https://www.centerjd.org/content/fact-sheet-punitive-damages...