>>395520778
You can make a mesh move, rotate, and scale in unity without the need for an armature. These operations don't actually cause any changes to the layout of the mesh. What an armature does is introduce a skeleton which lets you actually deform the mesh, like bending a joint or something. 

Something like a prop, such as a crayon or something, may not need an armature because it doesn't have to bend or deform at all. Instead, you can set it to follow along with your wrist bone, but the key thing is that the crayon doesn't need an armature of its own because it doesn't have to deform.