90% of people say this familiar idiom wrong

Perhaps you have used or heard others say one of these two idioms many times, with the purpose of arranging forces into a battle-ready position to prepare to fight the enemy. But is the idiom you know correct?

Which answer is correct?

In your opinion, is the answer “Army Arrangement” or “Army Arrangement” correct? Please write it down in the comment box below so everyone can know.

Trung Temple

Source: https://vtc.vn/90-nguoi-noi-sai-cau-thanh-ngu-quen-thuoc-ar835377.html