Lingard has done well lately but you're comparing him to the wrong players. Hazard has flattered to deceive as usual (not to say he isn't a top player), Sanchez has been bang average, Firmino is pretty good but in and out of the team and Mane has missed a number of games.
Calvert-Lewin has 3 goals and 6 assists, doesn't mean he's been better than this lot.