I agree with your point of view business management depends on the size of the business but one who is use to managing businesses can be able to run 2 to 3 businesses simultaneously.Busines management depends on the size of the business. However, a large scale business with branches in different location can’t be supervised and managed effectively by one person. This requires services of experienced managers. The numbers of busines that could be effectively managed by a person is dependent on the size of the businesses