Fans don't generally connect to the power supply; they connect to the motherboard. If you have more fans than headers, molex adapters for fans are usually of a pass-through design and can still be used to provide a connection to a 6-pin adapter. Fans don't usually draw more than a few watts so multiple connections are unlikely to be an issue.
You should see my daisy chained fan connectors. I'm running 3 fans off a single molex with those adapters chained together