It would certainly be an achievement for Celebrini or Michkov to duplicate Bedard's 72 point pace from last year. Both will have non playoff rosters to work with like Bedard did so its a good comparison. I'd say the likelihood of passing that pace would be pretty low. Michkov has a whole series of adjustments he'll need to make other than much less time and space. And then there's Torts and all that uncertainty. It feels like the Sharks are asking too much of Celebrini (and Smith). For various reasons, I don't see either of these players on the same level as Bedard.
For the apparent underdog Stankoven, I think the situation is completely different. He has been acclimatized. He's played 43 NHL games and managed a 40 point pace in those contests. 19 of those games played were some intense playoff contests. He'll be getting a premium centre to work with - either he stays with Johnston and Benn or they move him up with Hintz and Robertson to assume Pavelski's role, even though that task likely now falls to Seguin for the time being, until he gets hurt. Logan will eventually bulldog his way to that role.
You could argue that like Bedard, Michkov and Celebrini may see a higher % of powerplay time, They will both be formidable challengers, but I believe Stankoven will receive so much more help in the Stars lineup that he'll double his current pace closer to 80 points. I believe Michkov and Celebrini will need to at least duplicate (or increase) Bedard's rookie pace to win the Calder and beat Logan, who in my mind is the clear favorite.