Surely it does help.
From stats, ST who has better heading does score a lot more from corners than AMs even when AMs’ shooting and finishing are better. Saying that, defenders with very good heading skills may only score a couple from corners a season, if any.
With your original question, positioning mainly helps with defending attacks. When positioning reaches quite a high level, say 180%+, it does help greatly on improving those players into goalscoring positions. My DL/DC/DMC, who mainly operates as DL or DC these days, scores 10-15 goals per season even when his shooting is only around 10-20%. Such a low shooting stat should suggest he would not score, but excellent positioning surely overrides in those circumstances.
Winning is a form of art. Consistently winning is a show-hand of skills and luck.