Rivera. Regista. Nothing to do with the translation. A regista isn't a position or a role, nor is a fantasista. It's the description of a player's personality more than anything. It doesn't matter that Rivera played higher up the pitch, he was still the one who orchestrated the play and that's what a regista is. It just so happens that the most common position a regista plays in is as a deep-lying midfielder. A fantasista can play in a deeper role just like a regista can play an advanced role, it describes how they play the game not where they play.
It has everything to do with translation and your post only proves that. You're showing the Italian wikipedia and their use of the word, my point is that it's been used by English speaking Football journalists, bloggers and fans for well over a decade (and probably longer but I wasn't familiar with it then) for the description of a player I gave above. As you point out, it might not be the Italian use or literal translation but it's how it has been used in English for a good while now.