One had roof piece and took down yc1.
The other was clowned by maria saved and then took down a yc2.
Zoro getting anywhere between 1.5billion to 2billion makes sense
And Sanji getting anywhere from 800million to a 1billion flat makes sense
Zoro (off the top of my head):
-Messed up Apoo to get the virus antidote
-Cut up Queen's virus-gun
-Zoro cut a Number's club
-Zoro did minor damage to Kaido (more than Kid or Killer, but not much)
-Blocked Big Mom's attacks
-Blocked Kaido/Big Mom's giant attack
-Got up to defeat King
Sanji (had to look some of this up):
-Saved Momo (very underrated honestly)
-Clashed with King while taking minimal damage
-Sanji defeats two Headliners
-Sanji carries Zoro, protecting him, which is necessary for him to defeat King
-Sanji saves Chopper from Queen
-Sanji continues to fight against Queen and King to protect Zoro
-Sanji fights Queen 1v1
-Sanji protect an innocent woman from Queen, and finally defeats Queen
In terms of feats, I think Sanji rivals Zoro here. Keep in mind Apoo is the one feeding the information to Morgan. Apoo is a giant gossip, he's probably spent a good amount of time gathering information on everything that happened during the Raid, to make as much money selling the scoop as he could.
Even without all that, though, it's pretty simple: Sanji and Zoro defeated two Yonkou Commanders worth 1.3B+. There's no way they aren't both above that, now. Just because the fanbase underestimates Queen and King, it doesn't mean the WG/Marines would.