It isn't true, Lewa is a clinical finisher usually. When we check his stats on whoscored he isn't as bad as you say, don't exagerrate.Lewa was always missing sitters, compared to lets say Kane he is a poor finisher
Robert Lewandowski - History
Robert Lewandowski statistics – 35 years_old Barcelona Forward. Check out his latest detailed stats including goals, assists, strengths & weaknesses and match ratings.
www.whoscored.com
I think those stats tell which kind of striker he is, a great striker. And not sure Kane is a better finisher.