Answer:
They believed that if the federal government had control of the army and the militia it would be very dangerous, because the government would have a strong centralization of power.
Step-by-step explanation:
For anti-federalists, allowing the government to have centralized control of the militia would give a lot of power to the head of federal control, that is, it would give a lot of power to the president. This could promote a strong abuse of power, as the country's armed forces would be controlled by a single person, who would be too powerful to be prevented from acting as he wished.