The unique aspect about both Jason and the Neomorph is they strike fast and hard (remember how fast that Neomorph bit off that woman's head? And pretty much every one of Jason's victims were dead within 10 seconds of him getting his hands on them). While it doesn't have the same armor as its Xenomorph cousin, the Neomorph might have the advantage in terms of stealth, especially since the android in the film didn't notice him until he was right beside him. He might be able to avoid Jason's notice just long enough to strike!
But Jason also is pretty decent at stealth himself (remember in part 6 how he followed Megan from outside and she never saw him? Chilling).
Honestly, Jason has one distinctive advantage over the Neomorph: durability. He might take damage just as easily as the Neomorph, but Jason has come back even from being shot in the head and torso multiple times (once again, from part 6). Meanwhile, the Neomorph died after only a few shots in Alien: Covenant.
If you look at the stats, I think you're right: Jason has the advantage. He can take a bigger punch than the Neomorph. However, if the Neomorph used its stealth to its advantage and got a clean first strike, I think those odds could be pushed into its favor. If it could get even one bite in before Jason could react, he might have Jason nearly beheaded in the first moment of combat.
In the end, I guess it comes down to stealth and who gets the drop on whom... if the Neomorph played its cards right, I think he could beat Jason Assassin's Creed style. If not, then his ass now belongs to Jason!