Jabra strongest attack wasn't an air slash, it's focused on stabbing his opponents, also. By your logic Lucci is weaker than Kaku
And let's follow your logic, zoro knowing he can't compete with kaku decides to wait for an opening before slashing him
Sanji launched himself into the air because he didn't think about Jabra's Skywalk, he just underestimated him
SMFH.
This just proves you can't read manga ...
Who mentioned anything about an Air Slash ????
Zoro challenged Kaku's strongest attack with his own and showed he's a great deal stronger than Kaku that's Zoro's character that's why he says this before cutting Kaku "Bring on the hardship, it's preferred in a path of carnage".
Sanji tricked Jabra BRUH go re-read Sanji's fight :
Jabura: Uhahaha, so ya blocked one of my hands!! Too bad for you; if you'd gotten the OTHER kick in time,
you could have stopped ALL of my Shigan!!
Sanji: ...no, I had to do it...!!
The other kick... is to FINISH YOU OFF!
"Diable Jump"
(jszzz)