Page and Halper both could have been deep state agents inside the Trump organization. Just because the redacted docs refer to one person doesn't mean there wasn't at least one more. That makes sense from deep state's point of view. They want to run out the clock and hope the dems take over the House. If forced to do so, they could give up Page's name, knowing he was not the actual source.
For people like me who don't want to pay the WSJ to see the rest of the linked article, here is a little more from Strassel on youtube:
That article linked in: