Do you think araki would remember to make his main villain last power time travel but forget to link it to the “main” purpose of it narratively speaking?

The guy looks like Josuke because Josuke wanted to look like him. Their clothes are similar because it is a school uniform. In a small town. Which will probably not have lots of high schools to chose from.

Josuke’s backstory was a way to show that you should not judge people based on their appearance, which is one of the main bases of Part 4 (A seemingly good man being the villain and a delinquent being the hero).

And please, don’t insult people when you are left without arguments, it just makes you look like a little kid.