Sure if you can put the specific melee weapon on the other slots. But a bat, for instance, can't be put on the belt and can only be attached to the back. So say you generally use a bat, but you have a shotgun on your back, when you switch to the shotgun it just puts your bat away and you then have to go back into your inventory and re-equip it. It should just take the back slot once you switch to the shotgun and vise versa