I'm going to assume that you want rather realistic space combat, in that case autonomous drones are an absolute must.
In space, it's possible to predict trajectories of unpowered objects for thousands of years with accuracy of centimetres, orbital speeds are measured in km/s and there's no such a thing as "maximum range". Range is only limited by target's ability to evade projectiles - at range long enough, any change of velocity will count as evasion, so everyone will be either using missiles that can adjust for enemy course changes, or lasers which strike without warning and can only be dodged by changing course all the time. Space is so big, and lasers/missiles offer range so great that saturating area with kinetic projectiles isn't really practical at all - gatling guns are right out.
In practice, combat is most likely to take only a few seconds, maybe a minute, but less than a second actually matters, rest of the time is spent waiting for death as missiles and light beams scream through space towards targets that are only technically still alive. Shooting down missiles only works if you can do it far enough, otherwise resultant cloud of debris, still travelling at 50km/s relative to you, is going to be every bit as deadly as missile was.
All in all, space combat will be fast, brutal and deadly, completely eliminating human element from actual combat- when shooting starts, course of battle will be decided before you even blink, that doesn't mean that humans can't plan battle in advance, though. Remote controlled drones are unfeasible because of lag caused by distance. Only fully autonomous ships can be effective in actual space combat, and they don't actually need to be real AIs, calculating trajectories is easy for computer and relatively simple algorithms will be able to easily decide which ship shoots which enemy with which weapon. In addition, there's almost no difference between autonomous drone and missile - "fighter" drones can be used to launch smaller missiles first and later to ram the enemy.
I would expect humans to crew carriers/flagships that stay very, very far away from actual combat, a bit like modern aircraft carriers - they won't actually fight each other, instead they will be sending autonomous fighters and autonomous escort ships to destroy enemy carrier. Keep in mind that fighters and escorts will be smaller and more agile, thus they will be able to get closer to the enemy, so of course enemy sends his fighters and escorts to intercept yours. Since goal is to destroy enemy carrier, humans aren't actually safe, they need to be close enough to plan tactics before battle starts but far enough that even with decreased agility they are not immediately threatened.
Conclusion: Since even present day AIs are sufficient to control unmanned combat craft, there's no place for humans on board of combat craft. However, if your world lacks AGIs or sophisticated tactical AIs, humans will have to be dangerously close to be able to plan tactics executed by unmanned craft.
Disclaimer: All of the above goes down the drain if you add any of the following: shields, super strong materials, FTL engines. Human operated fighters will still make no sense, but human operated capital ships could.
