On any particular day, the TD safely transports guests to destinations, makes sure their luggage arrives, as well, escorts them to points of interest, and manages the on-site experience. The TD makes sure there are sufficient rest stops, and tries to find interesting places for those stops. At the same time, the TD looks ahead to future stops, and makes sure that the group is expected and the vendor is prepared. This is a complex task, and is impacted by road closures and unexpected challenges.
Those are the mechanics of the job, the tasks that need to be done for the itinerary to work.
That's only half the job, and little of the remainder is written down anywhere.
The other set of skills needed by a successful TD are "soft" skills, an ability to help guests enjoy themselves on the tour, meet other guests, experience surprises that add to their delight at being here, all while the TD monitors the group dynamic to see that everyone is included and having a good time.
Guests expect organizational skills in a TD, and will not really notice them unless something happens that the TD could have avoided with advance planning. Yet their memories of the trip do not come from this skill. Rather, it is in the "people" or "soft" skills area that guests build happy memories, or not.
Two skill sets, very different, each essential. A little water-walking wouldn't hurt, either.