I won't go through a long list of names, and I do take the point that you have to keep people happy, but I'm not saying we should sign a 3rd choice striker who is happy with 10-15 games, like Niasse.
I think we should sign another 1st choice/compete with Tosun level striker, and then DCL becomes your third choice striker. You need options.
It's a conundrum as in an ideal world we would sign another first team ready striker and be in enough competitions to need four strikers.
I take the point Niasse isn't at the level we need but if we're looking for fresh options off the bench to get you a goal then although you'd like to see DCL progress and improve Niasse would be your go to man. In the derby we needed fresh legs up top but if Niasse gets the chance DCL had it hits the back of the net, somehow, and we win the game. Which then leads us onto a more general point of do we take the long term view and invest the time and effort in DCL in the hope he becomes more clinical, notwithstanding the fact he might miss a few chances and cost us points along the way.
It's strange as Niasse is completely unorthodox, is unlikely to improve and half the time he looks like a Sunday league throwback but he's effective. He really shouldn't be succeeding at this level but he does. Maybe because he does things completely off the cuff so no-one is sure what/where he'll pop up next.