I think Yunli will be better than ratio in the follow up team for some reason:
1) she doesn’t relay in debuff to do damage so her damage will be more consistent m
2) she does blast damage which can be useful for those annoying minions while doing most of the damage to the main boss
3) she’s going to be attacked a lot of times because topaz is a hunt unit and Robin a harmony one and if I don’t miss remember Robin while she’s in ult has lower agro so you just have to put her next to aventurine and she’s going to receive a lot of attacks
4) She does a lot of FUA which translates in Numby having a lot of turns and Robin having more energy
5) and she also has better multipliers while buffed than ratio and she gets a lot of crit damage and energy so she’s going to be buffed all the time
I’d say probably, but it comes with the conditional of getting her LC.
If you use her in a Topaz + Robin comp (the optimal comp for Topaz and generally where Ratio would be replaced), you’d be dealing with Yunli hit RNG for every single attack, and considering the aggro splits between baseline characters, if you aren’t using her Ult, you’d have a 30% base chance for Yunli to be attacked individually.
This of course can be scaled up with positioning and wether or not enemies use AOE/Blast, but the base rates for being hit are even worse than Ratio’s FUA RNG. On the other hand, if you were to give her the LC, the minimum chance would shoot up to 70%~ which is much more manageable and consistent.