You are correct and flights can certainly be added if required. What is relevant is that although BA was the traditional server of Scotland by default, in the last 10 years the state of play has changed radically with large numbers of flights into / out of the Scots airports and lots less monies for all involved. Whatever way we look at growth, logic must surely lead to far better train services in the future city to city centre, because the LHR experience by air still is a trip time city to city of 4-5 hrs.