One of the reasons for Havertz finishing last year strongly was he mostly played "False 9" (essentially the striker) in that period. Had previously played support roles out wide. With Lukaku a certainty for most games in that position, I think it most likely hinders Havertz's scoring potential...
But for the sake of GW1, once we see the lineup, I think getting a CHE attacker offers a good opportunity, and then that position can be used to move onto a City MID for GW2.