Yeah he's dangerous when he's closer to the goal but for me I think a more balanced approach for him is in a 4-3-3 is to play him as the most advanced midfielder where he would help start plays and it wouldn't completely diminish his long shots and finishing.
On paper the idea looks great. But in order to really get it to work is we need a better CM than someone like Rakitic. We need someone who is not only more mobile than he is but someone who is stronger on the ball and can retain the ball and circulate it as well along with some creativity.
Someone like Thiago would work well with Coutinho I bet. There's also Arthur but there's still a question mark on him if he can come here and adapt to european football and prove that he is good enough long term for us.