What is the second largest city in Sichuan?

The second largest is the undisputed Mianyang, needless to say.

The third is not clear, depending on which aspect you are referring to, but in any aspect, it is not Guangyuan mentioned on the first floor. There are many cities bigger than Guangyuan, such as Panzhihua, Dazhou and Nanchong, including Neijiang. Are they not bigger than Guangyuan?

Personally, I think we should choose between Neijiang and Nanchong, but there is no clear statement about this.