I said the word "enough" which goes along with your idea.
Is not a swordman to the core is your claim which traslates into him not being enough of a swordman.
Don't difuse my words .
Accept that Oden even tho being a full pledged swordman in mind and heart lacked something to achieve the Kokuto rank( or maybe he just died early ..).
You are confusing stuff,
Cracker is a swordman yet he likes crafting more and making clones...
Oden is a swordman yet likes being free and exploring the world more. We dont even see where Oden is training or stated to be training coz he is a natural freak
Shanks is a swordman yet he doesnt look like he really is deep inti sswordmanship as someone who seeks to be WSS .
Zoro is really into swordmanship ... he doesn't have other goals/passions except training himself everyday to be the best swordman.
Like I said being X doesn't make you a hardcore fan of that X.
Oden Shanks shown no interest to being WSS or best swordman in the world ... I think that's the secret behind Ryuma Mihawk Zoro who clearly wanna be superior swordman!!!
Is Zoro gonna surpass swordmen like Mihawk Mihawk Oden Rayleigh at EoS? Yeah whether slightly to some ot clearly.
Does black blade makes Mihawk stronger than Shanks? No they were stated equals.
I don't wanna enter mihawk debate coz with black blade Mihawk hasn't even accomplished what Oden did. So please let's talk about other stuff.