I would be pretty surprised if unionized SK flight attendants being paid more in Scandinavia for my US-Europe/Europe-US flights would mean superior FA assistance in an emergency than a lower paid DL flight attendant.

Training can happen and work even with lower paid staff. And there is no guarantee that any amount of typical FA training by SK or DL is going to change how they actually respond in a real emergency. Training works, but a lower or higher salary may not necessarily make all the difference in the world In an emergency. In an emergency, loyal, low-paid locals can at times provide superior security to overpaid mercenaries in it just for the money. Maybe it sort of goes the same way with FAs. Oh wait. Highly-paid SK FAs are pretty loyal to SK — some even think they own the plane.