Sean
You may be right about not having to stick to any convention but I also tend to think that the gca's of that period, in the UK at least, "benefitted" from not having the same earth moving equipment they have now and perhaps therefore had to show a bit more ingenuity to deal with the lay of the land.
Not saying that was what happened here as it looks as though from the photo that a more conventional fairway design would have been possible. Either way, it makes for interesting golf.
Niall