Benefits (How this will benefit the server and game as a whole): Where we stand at the moment, I think that organization on the squad level is one of the major failings of marine fighting. Over time, the squads get broken down and mashed together, until there's just a sea of standard marines milling around with absolutely no leadership; in other words, Hell. This will take steps toward solving that problem as well as give the Squad Leader a new tactical tool rather than more weapons, giving increased importance to their strategic role in the battle and encouraging them to command more and run in less.
Details (Description of how you think this would work, the benefits, etc): So basically, my idea of the CommandHUD™ would be something similar in function to the already existing HUDglasses that the MPs wear, but with more of the function they have on vanilla SS13 servers. You can examine a player that's in the security database and manually set them to arrest and do other shit from their description. The Command HUD's major features upon examining a player in your squad would be:
1. Assigning fire teams - this is a big staple in the movie that we lack, and would be good for leads that like to organize. When you set each member's fire team (1-5), a number will appear on the squad HUD (below their icon if they're above PFC, or in place of it if they're not). It would look something like this (Crimson, I hope you'll forgive me for using your likeness, and everyone else, forgive me for my horrible MS paint skills)

People on fire teams together would be encouraged to work together and stick together, allowing them to function better together in combat since everyone has a partner to look out for. It would also let leads split up tasks better (instead of reading off a long, tedious, and attention-span-destroying list of names, he can simply assign Fire Team 1 to go watch the southern part of the FOB).
2. Modifying the squad chain of command - in the event that the specialist or SL himself is killed, the chain of command goes pretty haywire. Using the Lead HUD, the Lead can pick people to be TEMPORARILY next in the chain of command, so that if they are killed the squad isn't impacted too terribly. This would involve a few dropdown boxes for different positions in the squad line of succession, with each living squad member able to be selected from the boxes. (Not sure, will probably need to be balanced and refined)
3. Disciplining insubordinate marines - say Urist McBald decided he didn't want to guard the FOB and fucked off to the stratosphere with a belt full of AP. Should he survive, the SL can mark him for insubordinate behavior, creating an icon above his head for MPs to see and also alerting the MPs via radio or something akin to the Overwatch messaging system. This may also work to restrict their access to squad-related doors on the Almayer, such as prep.
Implementation (Optional, if you have an idea how to implement it): C O D E R B U S