Change the hitbox of the vanilla mobs

So there is this mod that im really enjoying (https://www.curseforge.com/minecraft/mc-mods/yarr-cute-mob-models-remake)
So there is an option to allow these models to actually fit the hitbox of the mob (Spider become smalls, endermans become bigger)
Problem is, id rather keep the player height look of some of the mobs.
Thing is, there hitbox do not match there look (spider hitbox being the one on the ground (aka real spider) and not the human like figure, silverfish hitbox being microscopic compared to the model itself)

so I was wondering if there was a way to edit the hitbox of the vanilla mobs so that I can force the regular player hitbox on them.

(EDIT: yes, I know, a thousand discussions for customs mobs hitbox but im sure I didnt see one for vanilla mobs hitbox)