Oda himself said that Kuro's "Shakushi" travels at roughly the same speed as CP9's Soru ability. The difference is that when Kuro uses that technique, he cannot see what he is attacking, or how far he is going, whereas CP9 have mastered this ability and therefore can. It was some fan question, where they asked which was faster.
So basically what I'm saying, is that there are probably alot of people there who have techniques similar to aspects of the 6 Forms, but are probably not of that martial art itself.