I'm not sure title chapters matter. For example, Jinbe and Robin got vs. titles, but Franky didn't. While yes, Franky's fight chapter was Sasaki related, it proves that Oda isn't consistent with "vs" titles here.
The fact that 1028 and 1031's titles are related to Sanji vs Queen but separated by 3 chapters already is something unheard of in this series prior to this. Both chapters only had like 6-8 pages of focus and not a full chapter of dedication. A lot of people were convinced that 1029 would follow up 1028 and be Sanji's full fight chapter, but here we are.
At the end of the day, it just depends on how much Oda wants to keep Queen and King around, and how much he wants to give the in terms of a moveset and how much progress he can make in a fight with the. 1 chapter gives you 16-17 pages to work with, and thats assuming the entire chapter is that particular fight. 2 chapters is 32-34 pages, far more to work with at any given moment.
Tldr: I just would like Zoro and Sanji to have 2 complete chapters worth of fighting and not chopped up bits like Franky vs Sasaki was or Ulti vs Nami (which barely constituted as a fight).