[Jake Raby]

Why would they have so high a variation on moving engine parts

Because time spent dynamically balancing the engine costs money. Accountants hate that, and they are in charge. It takes me 6-8 hours to fly dynamically balance an M96 engine before assembly.

Also, that heavy assed, 37.5# dual mass flywheel will mask the imbalance. Thats what the factory thought.