Well I dont have any sources on 20th century military commanders, I can tell you that modern army commanders still use big maps and plot points and troop movements. If you're plotting movements in enemy territory, then you can't just go look at it in person. They have to look at the options they have, and a map is the best way to do that.

Source: I'm in the u.s army and I work in the room commanders plan in (called a toc).

Somewhat related, the US Navy still uses what is called an "Ouija Board" (Just like the game) on its aircraft carriers, which is essentially a map of the carrier with little models to denote where aircraft are located, and colored markers (washers on the carrier I toured, the USS Carl Vinson) attached to them to denote their condition (i.e. damaged, needs fuel, ready for flight, etc). The board I saw had two levels to denote the flight deck (top surface) and hanger deck (just below that, where aircraft are stored), and was located on the flight deck level of the island (the "tower" that sticks out of the flight deck)

Here's an article that explains more about it, and includes a picture at the top showing the Ouija Board of CVN-69, the Dwight D. Eisenhower.