Is it fair to say that the "enfleshment" of John 1:14 was caused by the Word?

No, it is not.

The word is simply the will, expression, power and outreach of God in His oral decree. The same author John expressly shows the word as a 'which' or a 'what' and not a *person* who was 'with' God in the beginning. John recasts the essential core of God's interaction with creation (His word) by enlarging and reinforcing the simple introduction in his Gospel.

>That **which** was from the beginning, **which** we have heard, **which** we have seen with our own eyes, **which** we have gazed upon and touched with our own hands—this is the Word of life. 2And this is the life that was revealed; we have seen it and testified to it, and we proclaim to you the eternal life that was with the Father and was revealed to us.

If he meant 'whom' he would have said so. But no the 'whom' is now the one Jesus who is that *human expression* of God's will and intention. He is the one they can now touch and see because he is the word of God embodied. Certainly, the nature of the 'word' or 'logos' is totally *representative of God* in every respect - what God says will be, will be. This representation is now the human Jesus who also is the source of life, power and decree, being given this authority within God's sovereignty. 

The 'word', like Jesus when he was on earth *until* his resurrection to immortal life, is incapable of doing anything of itself/himself.

The idea of devising doctrine on some *perceived nuance* of Greek grammar, when the text is quite explicit (and supported by itself in other passages), is unsound exegesis to say the very least.