That doesn't make any sense.
Well, unlike Law's slash which is a huge topic for what constitute it and and by what percentage, CoA more or DF mastery more or just pure DF power, Zolo vs Pica is incredibly simple: CoA+Physicality (Pica's durability and Zolo's slash strength). There is no DF power concerned nor any special technique like BoAT as far as we know.
ZoloPhysicality (ZP) +ZoloCoA (ZA) vs PicaPhysicality (PP) +PicaCoA (PA)
Now what Zolo said is if PA>ZA, Pica would win. But that does not make sense because clearly there are still ZP and PP in the equation.
Aside from its magical ability to fight DFs, CoA is nothing more than an added armor that helps hit harder, so just physical addition, as Rayleigh said. So logic dictates that a character does not even need CoA and can still win against someone who has if his strength is much better than the opponent, enough so that the opponent's CoA would not help. Luffy has proven this by his fight against the Boa sisters where he overpowered Marigold's (or the other one) CoA-coated palm with his non-CoA kick.
So what Zolo said can only make sense if:
1. ZP=PP => if PA>ZA then the right side of the equation is bigger than the left side. Which I don't really have a problem with. That would make Pica quite competent LOL but it seems you and Sloan or Madara D Dragon all agree that even at base Zolo>Pica (ZP>(>>)PP)?
2. Zolo knows for sure he's stronger than Pica at base (Zolo can probably estimate Pica's physicality aka PP because Pica had once left the statue and fought Zolo with his sword IIRC), ergo ZP>PP, which means for the right side to be bigger than the left side, PA has to be > ZA. But here's a problem: If the difference between ZP and PP is bigger than the difference between PA and ZA, then even if PA is > ZA, the right side may not be bigger than the left side. Let use number to illustrate this:
ZP+ZA=13 > PP+PA=12 and hence Zolo still wins even if Pica's CoA is better.
Of course, you can argue that if Zolo knows PP and he of course knows his own physicality and CoA level aka ZP and ZA, it stands to reason that he can work out PA and hence his statement. Sure, but Zolo did not say Pica's CoA had to be much stronger or several times stronger than him (in order to compensate for the PP<<<ZP). He said that Pica's CoA just had to be stronger...so as long as PA>ZA, no matter how small the difference, Pica would win. Which brings us to point no.1 again...
So yeah, it may be very nitpicking but that's the gist of it. Zolo's statement does not make sense unless Zolo=Pica at base or Oda retcons his CoA vs Strength scenes and now Haki is the only thing matters...
so follow @captain kidd 's post, I either pick option A (Oda is not thorough with his dialogue) or D: Zolo's slash strength = Pica's durability.
There is a difference between ''the only factor'' and ''the deciding factor'', sure, but that is only when it comes to stuffs like job interview or something...where they judge you by many things and standards (porfolio, experience, uni grades, your conduct etc.) but ultimately there are a few that are significantly more important than others. But in this case, there are only 2 factors, Physicality and CoA, and none is more important than the other...and if a character states you only need one to win...which means you might as well cross out the other off the equation, which is wrong given Oda's past scenes (Luffy vs Boa sisters).