It is impossible to prevent fighting unless you spend every second of every day working with them. You can't do this. You will, at some point need to eat, or answer the phone, or leave, to go to the bathroom.

One male and one female are likely to get along. However, if both dogs are the same sex (or if there are more than two dogs) there will be fights.

Hurting them, in order to separate them is not going prevent fights in the future. When they fight, leave, because you will be injured. Also, their injuries are going to end up costing you a lot of money at the vets, and eventually, one dog will be killed.