Okay so can we talk about these tier rankings?
First, I've never liked the re-branding of "2nd Tier" into "New 1st Tier". Descriptively speaking, they ARE 2nd tier compared to SH, BJ, GZ, SZ. Period.
Second, 15 cities in this category is way too many. It should be chopped up...

Roughly, I think the division lines should be:
Tier 2.1 - Chengdu, Chongqing, Hangzhou, Xi'an, Wuhan, Suzhou
Tier 2.2 - Zhengzhou, Nanjing, Tianjin, Changsha, Dongguan, Ningbo
Tier 2.3 - Foshan, Hefei, Qingdao
And I'd probably move Nanjing into 2.1, above Zhengzhou.

I'd also find space for Wuxi and maybe Jinan in Tier 2.3.
Now keep in mind I've never been to several of these cities & haven't seen some of these other cities for like...10 years (should fix that).
So this is subjective and vibes based. Obviously. Don't roast me too hard.

BTW is Zhengzhou really nicer than Nanjing? I've never been to Zhengzhou besides Shaolin Temple so it's hard to make judgment call here.
And in my mind Dongguan and Foshan are like...the same place. Huge-ass suburbs of Guangzhou/Shenzhen. Should they be in different sub-tiers?