Both teams were, essentially, built by GM George McPhee.
The Vegas Golden Knights are an expansion team, so as its main architect, he put every piece in place, but he was also the Washington Capitals' General Manager until 2014, and the likes of goalies Braden Holtby and Philipp Grubauer, defensemen John Carlson and Dmitri Orlov, and forwards Alex Ovechkin, Nicklas Backstrom, Evgeny Kuznetsov, Tom Wilson, Andre Burakovsky and Christian Djoos were all acquired via draft, trade, development or signings in his era.
That's pretty much half the team in sheer numbers, but in terms of impact, it's more like over 80% of it. Although many will mostly remember that he was fired for trading an up-and-coming superstar-to-be in Filip Forsberg for an outdated periphery player in Martin Erat for a failed Cup run.
The top two Conn Smythe front runners so far are of course Ovechkin and the Knights' Marc-André Fleury, who has more Cup Finals on his resume than all of the other 45 players involved in the Final put together - all wins since 2009 - but there are other players worth noting.
Kuznetsov has taken Backtrom's place as the Caps' second-best offensive weapon and Lars Eller and Devante Smith-Pelly have found their niche, but the G-Knights' Jonathan Marchessault, William Karlsson, Reilly Smith, Alex Tuch, James Neal et al. have all proven to be too much to handle for such strong teams as the Los Angeles Kings, San Jose Sharks and Winnipeg Jets. Not only are they extremely quick and talented, but they've also proven to be opportunistic, scoring at back-breaking times, such as mere minutes after the opponent scored a tying goal, or at the end or beginning of periods.
Ironically, win or lose, the Golden Knights stand to become the best expansion franchise in NHL history, but the Caps, when they started playing in 1974-75, were the worst team ever,as can be attested by this except from their Wikipedia page:
The Capitals' inaugural season was dreadful, even by expansion standards. They finished with far and away the worst record in the league at 8–67–5. Their 21 points were half that of their expansion brethren, the Kansas City Scouts. The eight wins are the fewest for an NHL team playing at least 70 games, and the .131 winning percentage is still the worst in NHL history. They also set records for most road losses (39 out of 40), most consecutive road losses (37), and most consecutive losses (17).So this series will be historic in many ways.
I don't want to jinx it, and I won't be sad if it goes the other way, but I see Vegas taking this one.
Golden Knights in 6.