Golfers always dress smart, casual and in clothes that offer a degree of comfort.
Now you just have to decide which Golfers style is for you ? may I suggest Mr Poulter ?
Minus visor & putter obviously
Minus trousers too, well at least the style Mr Poulter wears. You'll certainly stand out wearing something like that.
My smart/casual clothes are very casual and I wouldn't feel appropriately dressed so personally I'd be in a suit. It makes ME feel comfortable.
I feel the same for interviews. And a suit is just a jacket and trousers that happen to be the same colour. A waistcoat and watch on a chain may be over the top though.
You've chosen to wear a suit and that is absolutely fine. You never know who you may accidentally bump into on the day, but as long as you are smart, suit or no suit shouldn't make a difference, after all that's what you've been told. Now forget the angst of clothing and concentrate on the job, good luck.