Thank you Mychael, I added your idea to the OP.

Yes targetting a friendly NPC isn't a big problem outside battle if you use the target filter "Friendly". Once you're in battle it becomes tricky.

By the way, your Path Companion is in your party when you have it. I never had someone else beside my Path Companion. What happens? Can you invite someone else while partying with the Path Companion? If yes, are PC's and friendly NPC in the same party list or are they in two separated party lists?