Can't they all mine together and then stop to attack if a pirate shows up? Or does it really take that long to quit mining?
Nope, they'll have to be mounting weapons on their ships and carrying ammo in their cargo holds instead of mounting mining lasers. Can't switch weapons without going back to a station. They won't be able to help mine.
"The whole problem with the world is that fools and fanatics are always so certain of themselves, but wiser people so full of doubts." -- Bertrand Russell (I think...)