We need creators, yes — don't think anyone would disagree with that assertion!
But I think Félix's scoring tendencies will get stifled if he plays with the combination of Martial and Rashford because he will be expected to a greater degree of unselfish creating for them (which wouldn't be ideal because he should have a more aggressive role). Keep regurgitating old examples, but players like Del Piero/Dybala/Litmanen (part scorers and part creators like Félix) reached some of the best form of their careers with no more than 1 predominant scorer ahead of them — all other attackers were either creators (Zidane) or wingers than maintained width (Overmars) or work-horse strikers than were tactically thorough (Mandzukić) — which gives us a decent idea of the type of balance Félix will need to realize his full potential.
I'll probably cop a fair bit of flack for saying this but if we are to sign him, one of Martial or Rashford needs to be moved on. As a duo, their skill set isn't particularly broad or symbiotic in the grand scheme of things, and neither is suited to a disciplined role — and while Félix is a capable creator, he should be a proactive executor rather than a constant facilitator for the other two. IMO, Something like Félix + Rashford + Sancho (who's an incisive playmaker/passer already and will add goals to his game in due time) would be a better template for the future because you'll have a really good mix of invention and movement to go with a fair bit of directness. Agree with the touch, timing and understanding bit, his vision of the game is refined for a young attack — very perceptive and well-rounded.