Not sure if you are talking about the same things, those are PPG near elite playmaking center and it is about how much the line score not just a player, but for sure peak Ovechkin could carry a line like few others, there is also something about how well player do together, Drai-McDavid are often paired because of just how well they produce, not because they can't without each other, LeClair scored well without Lindros, you still pair them.
get split at ES is that they simply aren't that good together. Crosby needs wingers who will do the defensive lifting for him,
Not sure on both account here, is that why Guentzel was such a good fit ? or that Malkin-Crosby were not that good together, that a post their prime phenomenon. Playing cycling hockey make the Dupuis-Kunitz particularly good for him.
Now it is often special occasion deployment (back from a break end of period need a goal, end of game need a goal), so there will be some scoring effect, but from 2008-2010
At 5v5 - 2008-2010
Malkin with/without Crosby: 62.4 GF % / 48.8 GF%
Malkin with Crosby: 4.63 goal per 60 minutes (much higher than when when he played with his most usual partner Sykora( 3.47)
Those are elite offensive output numbers
At 5v5 - 2011-2013
Malkin with/without Crosby: 70.27 GF % / 51.28 GF%
Malkin with Crosby: 6.28 goal per 60 minutes (much higher than when when he played with his most usual partner Neal (3.69))
Now everyone had crazy number when Crosby was on the ice during that stretch, but more than one goal being scored every 10 minute of play....., that incredible
After that they virtually stopped playing together at 5v5 (42 minutes from 2017-2019) with terrible result the little they do, but not when they were in their prime and did it more, it was just too much to contain even if they were not greater than the sum of their part happening at all with them.