Can anyone explain why it's believed this "would make no sense"?
Philosophy is not knowledge, it's pure speculation.
> law is philosophy, so cant be modeled by math
Law is not philosophy unless it was written based on sloppy speculations. In other words, what law is, depends on how it was written, it can certainly be modeled by logic and math methods can be developed for it too.
It's nothing new, lawyers have to master logic as part of their training.