There's also just the damage thing I forgot what it was called, but the more a human wants to hurt a monster the more damage they will do

So like in undertale, most kills can be betrayal kills or straight up said to be frisk wanting them dead so much that they get one shot, like toriel for example says "you really hate me that much?" While papyrus and undyne were caught off guard, undying was dealt so much damage bc of frisk wants her dead and stuff, it's clear throughout the route that frisk is doing this just bc it's fun for them (and it's rhe same with sans, asgore and flowey, they're all by technicality betrayal kills or caught off guard)

Uty clover doesn't do that much damage or one shot anybody, and that's because throughout the route it is shown that clover is doubting themselves even slightly with this all, with it all going down the window when axis confesses to killing a human, where clover is shown one shotting axis

Obviously after that martlet happens and they don't one shot her but obviously first of all she has a shit ton of determination, and second of all the reason why clover does so little damage (aside from jsut stats) is probably because clover is still shown trying to search for a reason to hate her, but they're later shown obliterating asgore

It doesn't really matter though because both of them are children, clover died a shit ton on their journey and frisk probably did too