Here's a common trap. AI drafts a course; a designer spends a day improving it; then the policy changes. Regenerate, and you lose the designer's work. Edit by hand, and you might miss something. Software solved this with the three-way merge.
Three versions, one careful decision
A merge compares three things: the original draft, the human-edited version, and a fresh draft from the new source. Changes the human made are kept; changes the source requires are applied; where both touched the same passage, it's a conflict for a person to resolve.
Separate meaning from style
Most human edits are about tone, examples and flow. Most source changes are about facts: numbers, steps, names. Treating these as different layers makes most merges clean.
Surface conflicts for review
When a human edit and a source change collide, show both with the source passage, and let the reviewer choose.
Ship as a reviewable patch
The result shouldn't be silently applied. It should arrive as a reviewable change, which is the Training PR idea. This is part of Coursecast's Change Intelligence roadmap.