only 2 armor legging bones

when trying to import a custom blockbench model for the leggings of my mod there are only two bones that I am allowed to map to. the bones are left leg and right leg. but there's no torso bone. the armor I'm trying to do is a set of faulds, but I cannot map them to the waist/torso. when I try mapping untextured parts to the left and right leg bones and leave the actual part of the armor I want unmapped, it just doesn't render at all. is there a way to work around this? I know vanilla armor has the waist bone because when using the vanilla armor model part of the armor is displayed on the torso (like with netherite), but for some reason this bone is not available for custom armors?? I'm on version 2025.3.45720 if that helps.