Conforming clothes are basically a character that overlays the base character. When you conform it, it adjusts it mesh to the shape of the base character. When you pose the base character, the confoming clothes character follows the moves of the base character Dynamic clothing is basically a prop. As such its shape is fixed. However the cloth room is able to deform the mesh so that it fits over the shape of the base character. But unlike conforming clothes, when you change the pose of the base character, dynamic clothes do not follow the moves of the base character. So you have to go into the cloth room again and recalculate the dynamic cloth prop. When you conform conforming clothes characters, they move with the base character. That is how you group them. With props, like dynamic clothes, you have to parent the prop to the bae character or another prop.