Running with an NPC that isn't listed as in your party makes for a pretty tough introduction to the job, too, since you have to find them on your screen, you have to "manage" your mouse cursor, and you have to click a moving target. That's making it more difficult than it has to be -- in a group, you can see what you need to see in the party list, and you can click them comfortably without having to "aim" at them.

So, don't worry. It's actually easier once you get into it. Maybe try Holminster Switch with your Trust buddies, to get a feeling for the job. (Avatar, not Story. Thancred is sturdier than Exarch)