You're wrong. We scored a lot of goals against pushover opposition (9 vs Bournemouth, 7 vs Newcastle, 6 vs Chelsea, 5 vs Palace, 5 vs West Brom etc), but equally there were numerous games when we were so lightweight up front we bordered on pathetic, and created next to nothing (Rags away, Liverpool home, Leicester home, Stoke away, Newcastle away, Sunderland away, Liverpool away, Arsenal away).
We need two new centre halves for sure, but we absolutely do need another forward as well (preferably of the powerful variety), and particularly given Kun's injury record. Relying on Sterling, Silva, Nolito and a 19 year old, who still falls only into the decent prospect category for me, would be foolish IMO