No, it is not an automatic failure. The fact of a mixed fleet of ICs and employees is not necessarily the issue. The problem with prong B of the test is that it prevents employers from contracting with workers that perform the same work as the business itself. Generally speaking, any time you have independent contractors performing the same role that is done or could be done by the carrier and its own employees, there is a serious risk of failing this prong. If the ICs are providing different types of driving services from employees (such as last mile and courier, or courier and long haul), that may reduce the risk, but only marginally. Having an overlap in duties makes it tough to argue why a specific worker is an employee (and entitled to benefits and such) when they are performing the same function or providing the same service as ICs.