I mean, they're supposed to be the best of the best, so it's kinda understandable that they're salty about being upended by some upstart rookie pirate (and are really overconfident about their own abilities in WW's case).
Speaking of Cipher Pol, I compared how Apoo took Kid's Punk Gibson (which mind you still hurt him a lot, hence his durability only downscaling) to how he took Guernica's Shigan, and Guernica's Shigan seems like it definitely did more damage:
Kid's Punk Gibson:
- Attacked an Apoo who was caught completely off guard (and Kidd was super pissed so there was no way he was holding back, which he doesn't even do anyways).
- Breaks one of Apoo's glasses (and a tooth). bruises his face, and makes him bleed from the mouth a bit, but other than that Apoo is completely fine, and after talking some smack to Kidd, he has no trouble using his sound attacks to unleash hell before resuming the fight with no shown weakening from Kid's attack.
Guernica's Shigan (yes, I know this is a Rokushiki attack, but we never see Guernica use normal attacks so I can only use his Rokushiki attacks to determine his AP at the moment):
- Attacked an Apoo who was actually paying attention to him and was definitely more on-guard (as shown by him using Buso Haki to defend himself).
- His Shigan made Apoo cry out in pain, bleed from the mouth, and knocked him unconscious for a moment or two, even with the latter using Buso Haki to defend himself (which he was not doing against Kidd). Even when Apoo is getting up right after, he's panting from the pain and damage from the attack (and somewhat quivering as he kinda struggles to get up at first for a sec), and even notes/complains about how much the Shigan hurt him.
Friendly reminder that Apoo was a grade-a moron for openly taunting one of the world's deadliest assassins.