Hologram ships, fighters, and missiles. Solid holograms are made of light but they can also vibrate the air and water around them to make sound too.
I'm not going to add an hologram to my mothership to make it look and sound like a sky whale now.
Recon drone have more sensors and longer range than the other drones. They can mark enemies and other objects of interest. They can allow you see through things like walls, rocks, and other stuff using 3D mapping and overlaying technology. And they can share their targeting data with other friendlies in the area. Because of the sensor array they can also highlight enemy weak points so you can do the most possible damage to them if you hit those spots.
Medic drone can help heal people and make small shields to protect them while reviving them as down person. They can also give friendly targets stimulants to enhance things like speed and strength as will as depressants to lower things like sense of pain. If the target is an enemy it can give them stimulants force them into an enraged mode where they are stronger and faster but are also unable to think clearly making them more likely to just charge in a blind rage. Or give the enemy depressants that slow down their movements, stun them, and even make them go to sleep. It can also scan enemy bio-data to tell you any weakness and resistances they have. For example an enemy might weak to a compound in plant and if injected in high enough amounts can poison and kill them. Can share it's biological data with other friendlies in the area so everyone knows what types of attacks are most effective on the enemy.
I make up more types of drones but you get the point. Not only would they be helpful to the player solo but if they are allowed to passively share data with other players in your group with option to share data with people outside of your group it would allow for greater teamwork and cooperation.
This also made me wonder if the enemy got a hold of such drone it could also be a risk since they will have more info on you :O so that means its vital to keep drones safe too hmm