Form practice usually involve multi-directional attacks. It is a very bad idea to be surrounded in a real fight and the fighter has to keep all his opponents in front of him as much as possible. It is, however, necessary to practice attacks in all directions as well as defences against attacks from all directions.
Keen senses and a good use of peripheral vision are skills that forms cannot develop. With a clear mind and keen senses multi-directional attacks make the fighter a one man fighting force capable of disposing of multiple opponents.