not any players but ally

Good resolution is to make it a requirement that the person is a registered pilot. This would also limit the amount of people piloting, because of lag.

One issue with this, is the person that is piloting (currently), can shoot all of the cannons and move by themselves. If you enter direct control mode, the person moving the ship could shoot the cannons.

Another issue, is that with having multiple people piloting a craft, you are risking the craft to get destroyed. For example; A person (lets say Jeff) is the person moving the craft and the another person (let's say Bob) is taking care of the cannons. Let's say Jeff moves the craft and Bob rotates a turret at the same time, you could easily make the turret disconnect from the craft, and then that cannon is rendered unusable now.