Field is not naturally attack-minded. His first reaction when receiving the ball is to turn backwards rather than forwards. They're both top players for us, but I think switching their roles would be beneficial.
Field is also probably, in my opinion a better defender. Varane has shown that he can pick a pass to get us moving forward, he has great drive. I would like to see him pop up more on the edge of the box, rather than setting up the attack then retreating.