Weight painting for grooms / hair is painful, transferring vertex group weight paints from parent mesh (body mesh) isn’t enough. There will always be manual cleanup. The weight paint per hair card won’t be uniform either, meaning deformation will be smeared and visually inadequate.
I created Groom Rig for blender, which automatically uniforms the weight paint on each hair card based on the root of the hair card, along with the ability to average the weight paints.
Results mean deformation is uniform, hair cards don’t break in half or twist partially.
the plugin is free for unfunded individuals and non-commercial use, check it out