So which one's correct?

>Monsters are much weaker than humans, which is why they lost the war and they're threatened by human 8 year olds

>Some monsters are actually stronger than humans physically, but humans' determination means if they have the will to fight, they can murder monsters easily

This confuses me, because in Undertale I was mostly convinced that humans are just much stronger than monsters, but then comes Deltarune and Susie is the brute of the group and can easily manhandle Kris.
Although that could be maybe because of Kris letting her?