No, it is accurate when:
- people say is a small island;
- Oda shows in more than one picture that is indeed the dimension of a city;
- the plan was explicitly to put Onigashima on the city itself.

But is a headcanon when you want to go against phrases and multiple images with one double spread lol.
I already told you before: if you want to day island>rubble, I can understand, but saying that Onigashima is bigger than DR is borderline comical.
- people say is a small island;
- Oda shows in more than one picture that is indeed the dimension of a city;
- the plan was explicitly to put Onigashima on the city itself.

But is a headcanon when you want to go against phrases and multiple images with one double spread lol.
I already told you before: if you want to day island>rubble, I can understand, but saying that Onigashima is bigger than DR is borderline comical.