your questions regarding the game rules (improving the interpretation).

Then the question arises as to the interpretation of the phrase "should be as short as possible." None of the red arrows meet this criterion; the shortest possible trajectory is the horizontal segment of the brown arrow.

I mean the shortest possible movement trajectory specifically along the path – the brown trajectory covers 2 path cells and then initiates an attack. The red trajectories go through the lairs of dragons, which are located on snow, and the movement covers 2 cells directly on the sand. The right red one – first, we position ourselves on the respawn cell to the right of the dragons, and then attack the lair of Efreet along the shortest possible trajectory.