The line count of a diff has nothing to do with how focused the patch is. Some PRs are simply larger than others due to the language in use or the nature of the code being changed.

Presumably a codebase in an array-oriented language would have miniscule PRs, which is irrelevant (discussion of PL merits aside).

Totally. Just click "rails generate" twice. ;)

I read it as a separate diff 200 lines later. But I guess pull requests could easily have that big diffs in a public repo