It took me around 4 hours to get my perfect town layout, but it really is perfect as far as I am concerned!! I didn't care about the initial villagers or the fruit or anything else, just stuff that I couldn't change later such as the position of the plaza, town hall and river. It is the first...
I was wondering this myself, and as far as I know, the diving trick is the only way to increase your chances.
This post on reddit explains it in a really great way, which made the difference for me, as I wasn't doing it optimally! I hope it helps you as well.
I have him in boxes right now, I'd like to give him away! I'm not sure how original he is, I rarely interacted with him, so I imagine that not much has changed from default.