I’m guessing strength is based off closeness to the Sun:
- Mercury
- Venus
- Mars
- Jupiter
- Saturn
Walcury is god of justice, so his fight needs to be symbolic in that regard. Feel like something like Garp and Sengoku or Smoker and Koby could 2v1 Walcury. Also Sabo and Dragon are another good option.
Zoro and Sanji will beat V Nasjuro and Mars, obviously.
That leaves Ju Peter and Saturn. They could lose to Kid and Law. I’ll just go with that, as Saturn and Jupiter are both gas planets meaning that Ju Peter and Saturn are probably a duo within the gorosei and hence will be beaten by another duo. Kid and Law are consistently portrayed as Luffy’s greatest allies, so this makes sense.