Mark,
`rbt land` does assume that your working branch has a different name than your tracking branch--that is, that you'd have origin/X, X, and then some local-only named branch. `rbt land` would then handle stamping and merging from local-only to X (and optionally pushing). We've found that's usually a safer workflow than committing straight to X, because it avoids unintentional pushes of unreviewed/in-progress code, and makes it easier to keep a clean commit history (if you're working directly on X, pulling will create merges, whereas if you have a topic branch you can choose to rebase or merge depending on your goals and preferences). Having a history full of merges can make it pretty difficult if you're trying to bisect to find a breaking change, and can sometimes make diffs on Review Board confusing.
That said, you don't need to use rbt land. If you really want to have people work directly on their local X branch, you can use `rbt post origin/X..HEAD` to post the in-progress changes, and then `rbt stamp && git push` when they're done with them.
David