Question about the 4th slot in Skirk's premium team

Hello! I don't think this has been asked before (or at least, I haven't been able to find a straight answer online). I've tried to look this up but most of the questions are from people asking what characters they can use as substitutes for Furina/Escoffier rather than specifically for the 4th slot. (I don't think this is breaking any rules, but please delete this if it is!!)

So, I have Skirk & Furina. I plan to pull Escoffier on her upcoming banner. I know Furina/Escoffier are her most important supports, & that the 4th slot is flexible, but if I don't have Shenhe or Yelan, who would you recommend I use for now? :)

Hydro characters at my disposal (excluding Furina):

1. C1 Xingqiu

2. C1 Dahlia

3. C6 Barbara

4. C5 Candace

5. C4 Aino

6. C0 Columbina

7. C0 Neuvillette

Cryo (excluding Skirk/Escoffier):

1. C5 Diona

2. C3 Kaeya

3. C1 Rosaria

4. C0 Mika

5. C0 Chongyun

6. C0 Freminet

7. C3 Qiqi

8. C0 Citlali

I also have other support characters, like Kazuha, Xilonen, etc., but I figure Cryo/Hydro is best for Skirk, right?

Thank you in advance!!