Just because "They traveled really far, really fast and made it here", doesn't require them to be super intelligent as a necessity. I would suggest the folks that built their craft and navigation and life support would be very intelligent but not necessarily smarter than humans. And certainly those doing the traveling wouldn't need extraordinary intelligence.
Today's aircraft basically fly themselves.
There was a time when driving an automobile long distances required you having a mechanic along. Now cars are driving themselves.
At some point the technology would become so ubiquitous that any moron could use it.
Just because “They traveled really far, really fast and made it here”, doesn’t require them to be super intelligent as a necessity.