I disagree, I think we've missed both unnamed player and James. They do possess that little bit of craftsmanship that can open a door that we have lacked this season.
Generally your guaranteed 10 goals/assist from Ghost every season.
A lot of Sigur,dss,on's assists and goals come from corners, free kicks (assists) and penalties. In open play he's so often a passenger who offers practically nothing. James was a different kettle of fish because he actually wanted the ball, his issue was more his availability and arguable lack of desire to play for us.
I'd argue that the two who have essentially replaced James and Sigu,rd,sson, for a fraction of the price, have delivered the same rate of assists/goals as we would expect of the Icelandic one after 10 games.
As an aside, I think the 'luxury' number 10 is generally a position I think is defunct in modern football. Not many top sides play with one because teams work so hard these days you need everybody to be fit and energetic, offering themselves everywhere, front foot and back foot.