Bear Grylls spent quite some time in nature, and he is also a veteran of the British Army, so he would be a must have for us if we would fight in forest, mountains.
Our forests on the game board protect You from artillery fire, so even if an enemy is launching close combat they cannot use their artillery support.
Mountains are a different story, defending and attacking from high ground both have its advantages.
Who would You go with if You could choose Your one person on the battlefield? Deep in the forest? High up the mountains?