I’m not sure how the pond was built for certain. Judging by the lay of the land my best guess is they damned up bottom land. The pond is down in bottoms and the rest of the property is uphill. But I can’t say for certain. I didn’t think it would be a problem but if auger style posts were a big no no then I would use them. I’m getting spare ones for free otherwise I’d build a floating dock.
I went for a floating dock and haven't regretted it. At first it seemed a little unsteady, but I quickly got used to that. Don't have to worry about water fluctuations, and I've seen fixed docks that were almost useless due to prolonged droughts. In one extreme case I had to climb down a good seven feet to get to the boat!
In the end, you should go with what makes you happy. No sense giving in to pier pressure.
