John 17:21 "Are in me" changed to "are in union with me."-New World Translation?

 John 17:21 "Are in me" changed to "are in union with me."-New World Translation?

The criticism towards the New World Translation here reads:

"The original statement by Jesus indicates his shared deity with the Father. The revision [of the NWT] undermines this by suggesting a greater separation between them."

The New International Version reads here:

"[v.20]My prayer is not for them alone. I pray also for those who will believe in me through their message,[v.21]that all of them may be one, Father, just as you are in[Gk: EN]me and I am in[Gk: EN]you. May they also be in[Gk: EN]us so that the world may believe that you have sent me."

Charles B. Williams in his The New Testament, A Private Translation in the Language of the People renders the above:

"[v.20]I make this petition, not for them only, but for all who ever come to believe in me through their message,[v.21]for them all to be one, just as you Father, are in union with me and I in union with you, for them to be in union with us, so that the world may be convinced that you have sent me."

This translator then supports the way the New World Translation has rendered the Greek preposition EN.
We are unaware that Charles B. Williams has ever been criticised for so rendering this passage.

So, yet again, we have a case of a critic isolating the New World Translation as if this Bible version has no support from any quarter. This is certainly not so. The critic says, as quoted above, that the "original statement" of John 17:21 is "are in me." But this begs the question why the critic does not go to the "original" Greek here to show that the way the New World Translation has so rendered it is not possible. It appears that what he means by "original" is what we might read in certain other English translations of the Bible! But we should all be honest enough to admit of more than one way of rendering a word or passage in the Bible from the original languages, Hebrew, Aramaic and Greek. The critic here does not even get close to doing such a thing and so has certainly not 'proven' his case! In fact if he has proven anything it is his apparent lack of objectivity and, hence, such a one as he must be treated warily when he criticises the New World Translation at any place.

Two other translations that we possess that agree with the New World Translation at John 17:21 with the Greek preposition EN are:

The Bible, An American Translation (E. Goodspeed) reads here"

"...Just as you, Father, are in union with me and I am with you, let them be in union with us..."

and the Complete Jewish Bible (1998) by D. H. Stern reads:

"...Just as you, Father, are united with me and I with you, I pray that they may be united with us..."