I just started to read the rules. At page five there is an example of movement from Africa that seem to me wrong: Africa is adiacent to Mare Orientale and Oceanus Atlanticus so why the army in africa had to move 4 times to go to Britannia and three times to Asia ? Africa-Oceanus atlanticus-Britannia (2 steps) and Africa-Mare Orientale-Asia (2 steps) ?
You are correct that there are less expensive ways to perform those movements. The examples were meant to reinforce the movement rules, not to show the most efficient path to the destination. Mainly we wanted to show that an army could move across multiple sea and land zones in a single move. In hindsight it appears this was more confusing than helpful...