Since it is a comedy main tag I would keep the cartoonish cover you currently have.
Seeing the new style with a bit of more realism makes me depressed. It doesn't feel like a story that would make me laugh.
I feel that your current cover perfectly depicts what people look for when they think of comedy. There are plenty of comedies with violence such as Rick & Morty. Having an extra serious cover would only hurt such comedies.
That being said I do not know how much of a shock you are planning to give your readers. You did place your novel under comedy main tag so I want to believe your main focus will be the comedy and passing all harsh elements in a comedic way just like Rick&Morty.
If you are planning to do a 180 turn in the atmosphere just like Magical Madoka then maybe comedy is not the right main tag. In a sense Magical Madoka did trick their audience by turning from a light hearted magical girls anime into a brutal psychological anime but it was a great work of art.
In conclusion, I vote for keeping the cartoonish cover. You should still wait for what other forum members have to say about it.
In this case I don't think there is a right or wrong answer per se since the change in style could turn into a great cover. You never know.
Edit---
I change my vote for the image that @river121693 shared. The idea River had feels plain genious and perfect for the situation.