They rather angered Kaido instead of risking for Luffy to awake his fruit. So they were more concerned for Nika.
Technically, they can be placed anywhere but don't act like them being last villains do not mean shit when the strongest top tiers have to fight them with Zoro, Law, Kidd, Sabo and Sanji at least. Confrontations between Dragon and one Gorosei is also possible.
Ofc this only counts if Saturn won't be defeated this arc but again, Luffy cannot beat Kizaru and Saturn at the same time. It's overkill and pure bullshit.
The whole angered "Kaido" thing is a bullshit anyway, from what they should be scared?
That is the same nonsense as people believe Kizaru could handle Kaido and BM together, these statements are just hypebole and nothing more. Everyone with little scaling knowing should know that Kaido and his crew are nothing in front of the WG.
What is Kaido doing if Imu send two Gorosei+one Admiral+10 Viceadmirals+30000 soldiers?
Saturn alone can trash people like Sanji,Franky and Bonney(who defeat Kaido second strongest commander) in mera seconds...
Two Gorosei could easily handle Kaido, while Kizaru and the viceadmirals would defeat the beast pirates.
The whole angered Kaido thing is just a hypebole, same as Sengoku said that the war against Whitebeard was a all out battle even thought the navy kinda low diffed them without even trying.
I have mad respect for Kaido feats, I mean alone the current chapter again shows how massive good Kaido feats are.
But if we can talk about who are probably stronger or equal to him, bet save on Gorosei since these guys also got massive hype by Oda.