Dalian isn't as premier as Hudong Zhonghua and Jiangnan, and both these yards at adjacent to each other, if referring to HDZ's Changxian extension. In addition, Changxing has a third shipyard, Shanghai Waigaiqiao, right next to the other two. The result you have here is a megacomplex, with multiple drydocks that can build a number of carriers simultaneously. You have to consider that this megacomplex while building the carrier, is currently building any number of 400 meter long containerships which are some of the largest ships ever built in the world, while also building 300 meter long LNG carriers for the Yamal LNG trade. The basin where the modules were first set, that's right next to the HDZ's extension, if not it is on the HDZ side of the island, and its right next to where the wharf where HDZ moored its finished LNG carriers for fitting, and its where the 075 had a stopover. The drydocks in Changxian can accommodate multiple carriers to be built simultaneously if needed. Your limiting factors would be money, how much powerplants you can make, how much crews and pilots you can generate. Dalian on the other hand, only has two large drydocks, and one would be used to make destroyers. If you want to make two carriers simultaneously, its actually easier to do both in Changxian which has the redundant capacity, scale and centralization. You let Dalian concentrate and build 052D and 055 on both drydocks. You can make Dalian do post 003 carriers but in my view, it would be less efficient since they have to tool for it as these ships are different from the Liaoning-Shandong.