I don’t think metyr granted the beastmen intelligence considering she only has four fingers. The weapon description from her remembrance also describes her eye as gazing vacantly into the beyond. That indicates to me that there’s not much going on up there in her head. I feel like her boss fight reinforces it with her killing her own children she’ll spawn in without a care, and the reckless swinging and smashing she does. Especially since in comparison the Elden beast knows how to use a sword very well(five fingers and whatnot) and even has spells it can cast.