It is an issue in Werner's case because we were warned by avid Bundesliga viewers that Werner, inspite his goal scoring record, wasted LOADS. When you analyse the goals he scored at RB, a lot of them were playing off from the left and beating the back line. RB was also built around him with creative midfielders that fed him constantly.
80% of clubs in the prem play a low block, and our current set up isn't built around Werner. You reduce the number of chances he has only highlights how poor a finisher he actually is.
Ask @killer1257, @Magic Lamps, or any Bundesliga watcher. They all warned us Werner misses loads.