Which is bigger, the deputy director of the Hong Kong Police Operations Department or the deputy director of the Management Department?

Flat, same size. However, the Hong Kong Police Force is a disciplined force after all, and military attaché s will definitely have more say and more support than civilian personnel. Moreover, in the absence of the Commissioner of Police, the Deputy Director of Operations is the commander-in-chief, and one person is above 10,000 people, so the Deputy Director of Operations will have more real power.