It's interesting we all think it's not a coincidence but don't think the only known connection accounts for the similarity - Brent's point notwithstanding!
But even if Mac did a little tee moving - and James, I think he did at RA 7, yes? - the green complex predates him, and that's where the distinctiveness comes through.
James, outside of golf, did the two areas have any connections, perhaps commercial? From where did Seaton, SA, take its name?
BTW does anyone else see these holes as essentially "military"? I have an image of golfers dialing in the artillery.
As usual, they came up short....
If anyone decides to do a military-template course, I say this template must go in!
Mark