i tried increasing the muscle size range, but while that increases the arms nicely, it makes the legs look all weirdly disproportionate and clip into each other. it really annoys me that the max beefiness for women is so much less than it is for men - is there anything i can do to fix this/ just affect the arms without the legs?

I believe there are atlesst couple of slider mods that you can slide arm,hand and etc.
I don't remember name of them but can be found easily with searching