Exactly. It's more of an analogy than based on any specific access to talent. There is great design talent in Scandinavia but thats just not enough to build a company.
On the technical side, I've not seen anything very impressive about their games, and their business practices seemingly consist of ripping off (later settled out of court) an indie developer who built a game in memory of his late mother, and dragging him into a protracted legal battle.
Edit to include sources:
https://en.wikipedia.org/wiki/King_(company)#Trademark_and_c...
Point being, unless you want to call gamification design, their success was far more based on engineering and business. Like you said it wasn't an original idea, but they could relativly quickly produce a clone of something and monetize. I'm not claiming that this is a particularly great way of doing business, just that it's inaccurate to say that it was design.