Idran, there is a difference in being a yeoman, personal assistant, the aide is more involved and more the "Face" of the general.
You have to plan the schedule out daily...keep the boss on time as he/she has meetings constantly...(with members of his staff or other organizations), people who want to see him (unlike Picard's ready room it looks like anyone can walk in without an appointment --i.e. Ro, Troi, Worf). you have to schedule times. In Trek-land ain't there hundreds of people on the ship, department heads vying for his attention (and for the First Officer too)
The guy who I worked for only had 2 people who could walk in his office (the XO and the Chief of Staff), everyone else went through me. And usually the XO and the CoS went through me as a courtesy.
When the General is out, he's meeting with people and has to briefed ahead of time who he is seeing, he had "read ahead" notes for almost everything.
Coordinating with other Generals aides as there can be pissing matches on who is better than who.
Yeah, I get Trek is a show and who wants to read about the mundane things, so it isn't really depicted like that. Closest thing was Vanguard in Book 1 when they introduced Reyes.
Bottom line, the aide a lot of times is the "Face" of the Captain/General they are working for. It just a real bad impression when the aide messes up on something, the boss looks bad.
In this case, Picard is one of the most prominent ship captains, not the just the Captain in charge of "Stembot Production" so he's gonna have LOTS of visitors/meetings/briefings/tours etc.
yeah in Trek-land you can say everything is computer automated or quicker ways of doing things. If I was a world leader (or the World Leader's aide) I wouldn't be impress if I had to work with Chen, who is representing Picard.
Again, there is a difference with Trek stories is Real life, so you have suspend belief at times, but I think it pushing it with Chen as the aide.
You got really stupid anal stuff to plan..."who is riding with who" in the caravan of vehicles? Who sitting next to who at meetings, even dinners can be painful as with the schedule of events and who is doing what.
Its a lot of hand holding and making the boss look good and you have to give reminders on what has transpired "at the last meeting" etc just to keep it all together.
Lastly, yep, the boss I worked for I suppose mentored me a bit, but also had other soldiers that he mentored that were NOT the aide and probably got more mentoring than me as they were more operational soldiers and not the aide like me.
Hope that helps.