It's a big difference tho. Jabura using his claws is part of his df. Basically an extra to his fighting style. Kaku's fighting style is based entirely in his swordsmanship.
Oh it's an "extra" is it? Jabura's strongest move in his strongest form uses claws, the Moonlight Ten Shigan.
Just like Jabura's style is based around punching but not all of it utelizes fists, Kaku's style is based around swordsmanship but not all of it utilizes swords.
All of his strongest techniques, Rankyaku, utelize his legs which is pure physical strength without the lethality/swordsmanship factor included with swords.
And then there's also techniques that Kaku uses that don't even use swordsmanship nor legs at all, like Giraffe Blast and those other weird moves he would use using his neck.
Kaku is not a pure swordsman and doesn't even use swords in the bulk of his attacks, the bulk of his attacks are ones that require pure physical strength.
If Oda REALLY wanted to make some huge indicator gap with Kaku being "clearly way stronger", he would simply raise Kaku's doriki. But no, he had it 2 fodder marine apart from Jabura and that was that.