Marv was able to withstand being hit full force by a speeding car and was able to just shake it off; I think his strength and durability is far superior to hers...
Add in Marvs willingness to kill and his viciousness, and I dont think she stands a chance...
The movie didnt do a good job of portraying it, but Kevin was absolutely superhumanly strong (as the graphic novel makes very clear; this movie is an adaptation of the graphic novel)...
Now based on the handcuff feat of Jessica's, you can certainly argue that she is stronger than Kevin, but Kevin is a much deadlier opponent than Jessica is...
Kevin actively attempts to cripple his opponents, is superhumanly fast/agile, and has those lethal claws...
Marv basically needed prep to beat Kevin...
Kevin would beat Jessica even faster than Marv would...
This is the movie forum. We go by what is shown onscreen. If you disagree, we can ask a mod, but I highly doubt it will go in your favour.
And Jessica has tons of other scenes that decisively put her above Kevin in strength, like casually snapping padlocks one-handed, slamming Luke Cage's head through a brick wall, tearing doors off cars, casually lifting and holding the back of a car as it tried to drive away, stopping a taxi with one hand etc. And in terms of durability, Jessica got full on rammed by a truck (leaving a massive dent in the front of the truck and messing up the engine) and only sustained minor injuries, and could also take blows from Luke Cage without taking damage.
So no, Marv is not "far superior" to her in either of those categories. Also, the OP says morals off, which means Jessica will also kill here.
Without morals, Jessica straight up just kills opponents. She doesn't worry about crippling. She either hits then hard enough to kill them or snaps their necks (like she did with Reva and Kilgrave). And besides, we are discussing strength, and the point that Marv cannot simply tank her hits like he could Kevin's.
Again, Marv should win, but he cannot use the same tactics he did against Kevin. He has to use skill and experience.
__________________ Never take life seriously. Nobody gets out alive anyway.