David Silva is, by your definition, nothing special athletically. Rabbi Mutondo is special athletically, as was Micah Richards. The latter does not make a great player, though it may make a player look like they are truly special, especially in their teens as their peers are not at the same athletic level.
Technique and vision always have the potential to make a great player. Think about what Pep does: he has consistently employed a combination of engineers and ballerinas: dictators of the play and dive bombers to deliver the coup de grasse. I do not know too much about Felix, but if he has David's vision, ball control and movement, with added finishing, I'd take him like a shot.