Someone unfamiliar with the ...

Someone unfamiliar with the mountains and forests cannot advance [the team]. One who does not employ local guides cannot gain the advantage.
Someone unfamiliar with the mountains and forests cannot advance [the team]. One who does not employ local guides cannot gain the advantage.

Quotes from the same author

You have to believe in yourself.
Can you imagine what I would do if I could do all I can?
The supreme art of war is to subdue the enemy without fighting.
“Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win.”
“Let your plans be dark and as impenetrable as night, and when you move, fall like a thunderbolt.”