The Panthers are OK. Their place in the standing isn't really their true talent level, but going forward they have some really fantastic pieces. Their best defenseman (Aaron Ekblad) is a franchise level piece to build around, he's like 19 and already one of the top ~20ish defensemen in the league. Between Alex Barkov, Jonathan Huberdeau, and Nick Bjugstad they have a really solid group of forwards to build around as well.
But this year's success isn't really sustainable, they're getting outshot consistently (5th last in net shots for), but they're getting a really high shooting percentage (goals/shots) and great goaltending. Good percentages aren't "bad", but it's really not common to be able to sustain an outrageously high shooting percentage, and outside of a few elite goalies it's rare to have a consistently above average save percentage. Luongo is genuinely very good but at his age (36) it would be hard to count on him continuing to play at that level. Every year there's a team like this that gets massively outshot but is bailed out by a good run of goaltending and/or shooting variance.
I'm not as familar with baseball analytics as hockey analytics but they're basically the hockey equivalent of a high BABIP team on offense, and a really low BABIP on defense.