Call of Duty is known for recycling as much as possible to pump out yearly games, I was actually surprised to hear they convinced management to give them time to rebuild the engine.
Besides, doesn't Bethesda Game Studios have more employees than Infinity Ward?
Elder Scrolls probably fits this category as well - not as much as Call of Duty but Bethesda probably has amongst the best RPG sales of anyone. They sold a hilarious number of copies of Skyrim alone.