We have heard that in order to win the Stanley a team needs a top tier goalie that has been there before. They also need that superstar who is able to carry the team when nothing else seems to be going. A proven head coach that knows the grind of the playoff grind and how to prepare his team and knows when to apply the gas and how to manage his team through the roller coaster ride due to experience. Then hone ice advantage becomes the next hot topic as that is needed as well if one is going to win the Stanley Cup.
I too have not heard these things. The Pens won the Cup in 2016 with a goalie with 13 regular season NHL games experience and, as far as I am concerned, he was still somewhat unproven in 2017 considering that he only played 49 regular season games that year.
They won with Byslma as the coach in 2009, hired mid-season and with no previous nhl head coaching experience. Sullivan was the coach in 2016 and 17 and he had only (head) coached a team once in the NHL playoffs and that was only in the first round.
And as far as superstars go, Crosby was injured and Malkin was heavily neutralized by the Red Wings' defense in 2009. They won that series through good defense and secondary scoring (like Max Talbot).
These are just the Pens' experiences. I am sure you can find other examples from other teams without having to look too hard.