It's quite normal for penthouse-size units to be at the top of the building. Even my old condo also have penthouse units on the top floor.

But it really depends on the project itself. Some may come with penthouse units while there are some with none at all and mostly consist of the typical layouts repeated at each floor.

Don't see it as an issue if you ask me. As long as I have a place to call home and content with what it offers, that's what matters.