Scotland's location in the NE Atlantic is pretty strategic - at least as far as the Cold War with Russia was concerned. Sitting on the east side of the Greenland, Iceland, United Kingdom (GIUK) Gap it forms a natural choke point for naval traffic and in particular submarines. Any future independent Scotland would be vital to NATO interests so the shape of any future defence force has a lot riding on it. Similarly with an ever warming world and decreasing Arctic ice new trade routes could potentially open up with Asia. In that case Scotland then becomes the northern gateway to Europe. So the needs of a defence force for an independence Scotland fall somewhere between a full-fledged military and a heavy duty coastguard / fisheries / border protection force. Even if the country chose to spend money on the military it's not clear that it needs to do everything. Instead concentrating on certain areas such an anti-submarine capability, mountain units, air-sea rescue and special forces might be effective and allow the country to play a role in the world without resorting to warmongering to justify the expense.