Pig Of The Hut I can totally understand 6-4 Jax, but I feel that because of the insane metagame involved, it could be a 5-5.
Jax isn't easy to zone in a fullscreen battle since he always has the benefit of dashpunching in and closing the distance between Kenshi. He's out of EXSC range and can DP through far overhead slash and teleflurry. This makes the Kenshi player want to bait the Jax by doing midscreen overhead slash, or dash forward into SC. It's like he has a Reptile dash effect in this area.
That sets up a metagame. What if Jax reads that the Kenshi is going to midscreen downslash and the Jax player does a far GP into EXGP, or worse, into ex DP (I think he's always going to be out of combo followup range). That means Jax just got a terrific advantage on the fullscreen tradewar. If the Kenshi tries to read that Jax does a far GP, Jax DPs in to give the threat of being closer to Kenshi. Whiffed SC could lead to DP or a GP punish on a read.
Kenshi dominates Jax at the midscreen range, there is no question about that. SCs are Jax's worst nightmare where downslashes and teleflurries fail to be, but then if Jax is SCed again to fullscreen, that brings back the threat of far GP to Kenshi, which can trigger Jax's GP cancel game as well. (even though that fullscreen trade war depends on who has the life lead, if Kenshi has an insane lifelead, it's in Jax's best interest to get in ASAP).
Jax obviously beats Kenshi upclose because of his hitbox, which means Jax is going to have an incredible time tick-throwing Kenshi as well as mixuping up almost all of his strings, regardless if his overhead shoulder is interruptible. Jax's normals I feel are too fast for Kenshi to have a great answer upclose besides D1 SC, EX SC, etc. If Jax blocks a D1 SC at point blank, can't he still get some pressure because of his fast normals?
If Kenshi blocks Jax's DP on Player 2 side and has no meter, that means Jax would have a teensy bit of frame advantage since a blocked DP is neutral. So even if Kenshi blocks Jax's DP, it's a lose-lose. (Just a little observation of mine, totally subjective and all theory)
Jax can harass Kenshi on oki with GP cancels out of SC range, DP crossups to mess with Kenshi's head (less useful and practical, but still there).
In the corner, it's just...bad for Kenshi due to his lack of mobility and Godzilla hitbox, regardless of his gallons of armor.
This is completely my opinion and I'm open to debate and any corrections to flaws. I don't completely disagree with 6-4 Kenshi, but the MU is not "Cage on steroids" per se since I feel that undermines Jax's ability to use his GPs in this MU on good reads, and Jax's ability to get in is much safer than Cage. I main both characters and I have a completely different experience using both characters in this MU.