not a Old course history specialist but
the course is played following the path of the marching stones that you can see on the course every 1/2 mile or so, if I'm correct.
maybe they just started playing along the path they followed for a long time to the Eden estuary. The basic clearing was done and at least, while playing, you were going somewhere.
it was also probably easier to think of playing on the low grassy pieces of land mown by rabbit and shhep than thinking of clearing and establishing acres of turf in the dunes