You don't actually need to use boots and bandages...
Most boots actually restrict full range of motion. They also hold in heat. Too much heat creates cell-death. Which, obviously, does damage to the legs.
My friend's gelding rode in boots all his life. (Hunter school horse for 17years. Yikes! He's now immune to all sedatives and tranquilizers commonly used on equines, but that's another story). He has white scars on his legs from where the straps on his boots created too much pressure and turned the hair white over the years.
If you're doing high level eventing, or jumping, or cutting, or you have a clumsy young horse, then yeah, throw some polos on. If not, you don't need boots or polos.