trestres, forget about polish, bugs, graphics, new gameplay, innovation...
this is the answer to your question and comparison, no two ways about it:
Nintendo has less than 4000 employees. Around 3750. Electronic Arts alone has twice of that. Combined for all the games you listed, the emloyee total is at least 15.000. Nintendo also makes hardware, most of the other companies don't. So overall, the others have at least 5 times as many employees working on games.
Oyvoyvoyv said: