'Overcome' in the Bible

After he had overcome Sihon, king of the Amorites, ruling in Heshbon, and Og, king of Bashan, ruling in Ashtaroth, at Edrei:

And the Lord said to me, Say to them, Do not go up to the attack; for I am not among you, and you will be overcome by those who are against you.

And when the Lord has given them up into your hands and you have overcome them, give them up to complete destruction: make no agreement with them, and have no mercy on them:

Give ear, O Israel: today you are going forward to the fight; let your heart be strong; do not let uncontrolled fear overcome you because of those who are against you;

By the power of the Lord, those who take arms against you will be overcome before you: they will come out against you one way, and will go in flight from you seven ways.

The Lord will let you be overcome by your haters: you will go out against them one way, and you will go in flight before them seven ways: you will be the cause of fear among all the kingdoms of the earth.

They will be wasted from need of food, and overcome by burning heat and bitter destruction; and the teeth of beasts I will send on them, with the poison of the worms of the dust.

How would it be possible for one to overcome a thousand, and two to send ten thousand in flight, if their rock had not let them go, if the Lord had not given them up?