Read the post over again slowly. Not surprising that you seemed to ignore a section I said. No winger like that can take you to the promise land unless they have a dominant center accompanying them. I repeat, unless they have a dominant centre accompanying them. Kane has Toews.
In order to be a contender, you need a centre to control the match up game. Its important when the game gets tight. This is common knowledge and I'm sure you already know this, you just don't want any negativity around ur boy Gaudreau.
Not sure that the Conn Smythe argument holds water, Justin Williams is on that list and he's certainly not in the class of elite scoring wingers. The Conn Smythe in particular I think lends itself to being won by goalies and by upstarts - guys like Williams who are not elite but got hot.
The Hart I think would be a better measuring stick, or looking at the list of cup winning teams and seeing what they had on their roster. The Hart is a mix of Centres, Wingers and one goalie - but none of those winners didn't have a good linemate (except maybe Joe Thornton in his first year in SJ, he turned Cheechoo into a star).
In terms of cup winners, you could make an argument that the 2011 Bruins didn't have an elite forward, but other than that the last 10 years worth of cup winners all had an elite centre (or two, see Pens), not all had an elite winger, lots had both.
The moral I take from it - elite centre is a must, supporting cast must also be good, and don't trade away elite young assets because the core of literally every team on the list for the last 10 years was drafted by the team they won with.
Also, lumping Gaudreau in with Patrick Kane is premature, he has to earn that and one ppg year doesn't qualify. Gaudreau looks great, Kane is the reigning Hart+Art Ross winner, there's still a sizeable gap.