From what I undestand from the specification (page 169/170) it takes the
first matching navigation rule. So for your third case, it checks the form-action, and if that doesn't match, it checks the from-outcome.
I agree that from-action alone is very helpful, but the combination has its uses. Though I always try to keep thinkgs simple, so I can just map outcomes with views, indepentend of from-view-id or anything else.
