Good post and I have very similar thoughts mate, i think we need to accept hes a 10 - 15 goals a year man, i think that is the limit of his goal scoring ability. But i think we also think to one dimensionaly when it comes to strikers. Look at Mordor and how they play, Firmino in a way is their DCL, he is the decoy, he occupires centre backs, the player who creates the space, who stretches a back four when needed, the occupier in a way, then chips in with is 10-15 goals. Hes in the team ahead of the likes of Sturridge who has in the past proved a 15-20 goal a season man. Its a different way of thinking and like Mordor we have to get our heads around, thinking as a functional front three rather then just one up top.
We do need support in those positions however both left and right and up top. We need different player types. What struck me recently was Silva referring to DCL as his target man type and his preference would be a pacey forward to compliment him.
If Gylfi, Richarlison and DCL can manage 30-40 goals a season between them, the 20 goal a season striker isnt (not that we dont need different options in the front three) necessary IMO, equally anything added in those front three positions has to offer variance and end product. They can all duke it out together IMO.