Is a #1 necessary though? I don't know that you need a true #1 to win. Florida just won with a team defense approach of a trio of #2/3 types (Ekblad, Montour, Forsling) and then a trio of #6's (Mikkola, OEL, and Kulikov).
I think the idea that you need a #1 is (and sort of always has been) a myth. Too many good teams out there that just have a group of solid D-Men and have success to think a #1 is an essential need. If you luck into one via the draft, great. I don't think it's something worth holding out for or trading for though given the cost is historically prohibitive.
Plus, the Sharks have had three #1 defenseman types over the years in Boyle, Burns, and Karlsson. How much did having those guys ever really elevate the team over where they were before we acquired them? Plus none of them were impact defensive defenseman. I think Doug Wilson, having been a high-end defenseman had a blind spot there while he continued to ignore the fact that the Sharks team had pretty weak wing play.
Now, you want to gift the Sharks a guy like Nicklas Lidstrom or Chris Chelios, I'm not going to say no to those players, but the Sharks have so many holes on their roster that short of getting too many centers (assuming Celebrini and Smith work out as your 1/2), as long as the Sharks are identifying good players at any position that lift up the overall talent of the team, I'm fine with whomever they pick.
From a personal preference, I'd like to see the Sharks become a high-end puck possession team after having to watch too many years of dump and chase hockey, but I'll be content with whatever wins.