The best - and probably only - example would be Vegas.
But people will say they were "gifted" a very good team with a generous expansion draft.
Maybe St Louis to a degree as well?
I think it's pretty tough to win a cup by committee without standout talents. A lot of things have to fall your way like getting career years from multiple players, hot goalie streaks, and favorable match ups. Perhaps it's more possible now in the salary cap era than it was in the past.
I still think the proven formula for playoff success starts with having an above average or elite core of about 4 players. Goaltender, Defense, and two Forwards (playmaker and a goalscorer).
Goaltender is tricky because of the long development time and shorter number of prime years for goaltenders. An above average goalie or a goalie on a hot streak can be substituted for short stretches. You don't need to use a high draft pick to find a goalie, there's plenty of value in later rounds. A good drafting and development system needs to be in place as it can be very difficult to address goaltending needs from outside of the organization.
A true #1 Defender, who can play any situation and eat 25-30 minutes a game is still highly desirable to anchor a defense. These players take time to develop and it's extremely rare for a team to trade one, so it's a player you have to draft and develop. The best ones are usually drafted in the top 10.
An elite playmaking center who can play in all zones is the cornerstone of most cup winners. along with a standout goalscorer on the team to fuel the powerplay. The elite centers typically go in the top 5 picks of the draft, goalscorers are a little more difficult to project, but usually go in the first round (but not always).
I think you need about 3 years of top 10 picks with at least 1 of those being a top 5 pick in order to build a core that can compete for a cup. Sure, it's possible to find some gems in the later rounds, but it's very rare to find a core forward or defenseman there.
Do we want to delay the inevitable rebuild for a few more seasons to try and make the playoffs or rip the band-aid off and start now? I can see merit in both sides.