What does Joshua 17:16 mean?

But the people of Joseph said, 'The hill country isn’t enough for us, and the Canaanites living in the valleys have iron chariots. They’re in Beth Shean and its villages, and in the Jezreel Valley.' Joshua 17:16 - Modern Text Bible

(They push back, saying the land available is too small, and the Canaanites in the fertile valleys are too well-armed to defeat.)