I guess, you will see a lot more parallel branches with Pijul compared to git.
Assume you change file A, commit, then change file B, and commit. In git there is a dependency from the second to the first commit, because the state of the second is derived from the first one. However, the changes are unrelated because they are in different files. Pijul understands them as parallel unrelated changes (although with different time stamps).
(disclaimer: I infer that from using darcs many years ago. I never used Pijul)
Well, it depends. In practice, I think the number of branches is similar.
In theory, the number of possible branches is much, much greater (arguably infinite) for git. Commits have their own metadata, so just amending creates a new commit. Patches are immutable, and there's no independent artifact like a commit that incorporates the current set of patches.
Furthermore, darcs (and I assume pijul) absolutely let you make multi-file patches.
Assume you change file A, commit, then change file B, and commit. In git there is a dependency from the second to the first commit, because the state of the second is derived from the first one. However, the changes are unrelated because they are in different files. Pijul understands them as parallel unrelated changes (although with different time stamps).
(disclaimer: I infer that from using darcs many years ago. I never used Pijul)