Before anyone just FRA trains for Lucci I just want people to consider the match a bit more. He has no reliable way to even hurt Jack due to the nearing one-shot stat difference without dura neg, something he doesn't start with. Meanwhile Jack can set up any type of trap he wants that can easily slice through that Lucci can't even see because he doesn't use his Kenbun, not to mention his base Hybrid speed advantage is useless against Jack, if he even goes Hybrid before its to late to avoid a trap or an attack. He only gains an advantage with Soru, a technique he in-canon neglects to utilize effectively in the situations where he needs it the most. Jack has a basically infinite reservoir of weapons that can do significant damage to Lucci at any time, so even in close-quarters, Jack can kick up some dust and even that can become a fatal weapon.
Jack is: Stronger, smarter, has a terrain advantage, and can turn literally anything he gets his mits on into a weapon capable of severely harming Lucci, meanwhile Lucci's advantages are Soru and Rokougan, one he doesn't even start with and the other I've already proven isn't the ultimate advantage it's posited as.
That's my take, and I'll end it there.