Perfected Praise Vs Ordained Strength

[Andrew]

"And the blind and the lame came to him in the temple; and he healed them. And when the chief priests and scribes saw the wonderful things that he did, and the children crying in the temple, and saying, Hosanna to the son of David; they were sore displeased, And said unto him, Hearest thou what these say? And Jesus saith unto them, Yea; have ye never read, Out of the mouth of babes and sucklings thou hast perfected praise?" Matthew 21:14-16

So the children were praising out loud in the Temple crying "Hosanna to the son of David" as it was written in Psalms 8:2

but.. what exactly does Psalms 8:2 say in our KJV?

"Out of the mouth of babes and sucklings hast thou ordained strength because of thine enemies, that thou mightest still the enemy and the avenger"

Wow!! Totally misses the point! Or Jesus misquoted it, why didn't the chief priest and scribes rebuke him for such an obvious error in quoting scripture?

Let's go to Psalms 8:2 in the Septuagint (LXX)

"Out of the mouth of babes and sucklings hast thou perfected praise, because of thine enemies; that thou mightest put down the enemy and avenger"

"perfected praise" > "ordained strength"

Thoughts?