For the expansion draft, each team could protect either 7 forwards and 3 defensemen, or 8 skaters regardless of position. Team's choice. Each team could also protect only one goalie. This was better for Vegas than for the teams in the last expansion draft but the owners and league agreed that they didn't want to see expansion teams in the future suffer as long as the previous teams. Regardless, Vegas was built with basically the 8th best player and lower from each team. A bunch of 3rd and 4th line players.
It just so happened that the Penguins who two goalies who could start for just about any team in the NHL, and once MAF wasn't protected he was a no brainer pick. A good goalie can carry a team a long way.
Two key players for Vegas, Tuch and Karlsson, were traded to Vegas - not drafted. I believe Vegas was also allowed to sign left over free agents after the initial NHL signing period and before the expansion draft. i.e., players that any team in the league could have acquired.
No one predicted this kind of success for Vegas prior to the season. Go back to October and everyone was picking them last or close to last. It is a remarkable story of building a team, coaching and players coming together to succeed. It is likely one of the top 5 greatest sports stories of my lifetime (born in 1971).
Vegas looked overmatched last night but that was a hot crowd they walked into. I predict they'll look better in Game 4.