The only thing Marner was better at was 5v5 p/60.
That is not true. You're ignoring primary point production, and putting an emphasis on goals, while comparing a goal scorer and playmaker. You're also ignoring entire relevant game states for these players, because they are in favour of Marner. You're also exaggerating the difference on the PP, while downplaying the discrepancy in a game state that makes up the majority of ice time. You're also ignoring the bigger sample, where Marner has shown to be equal to or better in everything except PP goal scoring.
If leaf players had FAR better stats and p/60 stats in the playoffs, there's NO WAY IN HELL you'd be arguing that we can't look at playoff stats.
I am consistent in how I apply methodology. Comparing and emphasizing small sample playoff production in the way you are, with zero consideration for impacting factors or the sustainability of results, is highly misleading, and it has nothing to do with which teams are involved.
What this has shown me overall is that Rantanen steps up in big games far more than Marner.
That's not really supported by anything.
So, in other words, Rantanen didn't allow BETTER goaltending stop him? He and his teammates scored on them and made them look bad?
In case you somehow haven't noticed, goaltending is way more variable than anything else. Goaltenders play better or worse, all on their own. You literally contradict your own statement, because if his teammates are scoring on them as well, it's clearly not attributable to Rantanen.
You say Columbus's goaltending was great.
Columbus' goaltending
was great. That's not a debatable thing.