Ooh, that's cool. I wonder if the monotsuki are all intelligent or if it's only Hime that gives them some sort of lucidity.
Consider that the MT that abducted Frena was pretty chill even though Hime wasn't there, but the one that attacked in the forest was not. We've got a wide range of MT behaviour on display that doesn't necessarily support that Hime is the common factor.
There's almost certainly a connection between the MT and Frena/Hime/Isana, but it's probably not that the MT become intelligent in their presence. To use another Nier Automata comparison: it could be like the race of Machines. Most are functionally barely sentient animals, but some are notably more complex like Pascal or Adam and Eve. That's a common theme in post-apocalyptic stories.
It would not surprise me if it turns out that most Monotsuki are raging beasts, but some are intelligent and have formed some sort of society with it's own plans and goals. Wild animals are not particularly interesting antagonists, but organised and intelligent creatures strongly associated with the natural world versus a society that is explicitly walling themselves in around the ruins of a former technological society is potentially pretty cool.