I don't think drones should be left there to guard things automatically. Thats just wrong.
Yes I like the defend command, and we had a very good thread a long time back with lots of different commands, and possibly even new types of drones to fill some roles like missile defense.
Yes they are slow to deploy, and won't attack past 20km presently, but they also never miss, no matter what the range and size of your target.
I agree the drone interface should be given an overhaul, and you should be able to group some drones, so that one command issued would send drones in that group to do that task, and you could command another group to go do something else. It would be far quicker then trying to multi-select more then one, send, then multi-select others. Basically why no one probably does anything other then Select All - Attack when necessary.
I think this was one of the good threads:
Cro Ramel's crazy drone ideas. (Not suitable for children.)