Too many! Well maybe not, I thiiiink.... 5-6 of them? It just feels like a ton of them because 3 of them are just a few space from one another right in front of where my retail and town hall are... so I had to work my paths around them and it's really irritating... But besides those three the other's are out of the way and I don't mind them really.
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)