Zibanejad, with all due respect, should not be the #1 C on a cup contending team. They need to get a legit #1 C like a Draisaitl. Breadman has gone missing again. And overall their top six has too many soft players.
I think Zibanejad and the others are doing fine. It's just that they meet an extremely good defense and maybe the best team in the league. Stacked with quality players.
It's always hard to evaluate players but I think it seems you don't need superstars to win the cup , it might be better to have quality distributed along the whole team instead of a superstar. Look at Vegas last year, Dallas this year and Florida too. (now doing better than Edmonton and Colorado)
(And as for Zibanejad he scored a lot of points against Carolina, (14 points total now - same as Panarin and only Trocheck doing better) players tend to go up and down during the playoffs due to injuries, opponents putting their best players against them etc. I mean , for every great forward there is an equally good defenseman.)
Rangers is maybe also softer but also a very different team than Florida, they do not rely on putting pressure on their opponent every shift - instead they punish their opponents with quick counter attacks, great pp and a lot of players that can finish.
Still I think Florida will win this, because it seems Flordia is stronger and Rangers also seem to have som injury problems.