'Expert in War' in the Bible

Of Zebulun, such as went forth to battle, expert in war, with all instruments of war, fifty thousand, who could keep ranks: they had singleness of heart.

And of the Danites expert in war twenty and eight thousand and six hundred.

And of Asher, such as went forth to battle, expert in war, forty thousand.

They all hold swords, being expert in war: every man has his sword upon his thigh because of fear in the night.