I was very disappointed to find two of them in the same area together, I could have had a villager house sitting there. (They're right next to the cafe)
I have 7. Some of them are placed super close together too. The one around the town hall annoyed me at first, but I actually use it as a decoration now in my plaza. I built a stone tablet a few spaces away from the rock to create a sense of balance. The others are all in manageable spots too. None are really much of an inconvenience.