Then there is the true grey area: one person worries a first draft, another person edits, rewrites, refactors, implements from scratch... at some point, they have done more work than the original author. When is that?
Our recommendation is to bias your credit policy in favor of rewarding the behavior you want to incentivize. Need more reviews? Maybe consider giving all reviewers co-author credit. Whatever you want people to do more of, make your contributions and credit policy reward that.
recursive