According to a March article in the Athletic, the top 16 drafted NHL D prospects are Nemec, Clarke, Nikishin, Jiricek, Edvinsson, Hutson, Zellweger, Reinbacher, Simashev, Mateychuk, Willander, Molendyk, Luneau, Morrow, Bonk, and Broberg.
Depending on your value of offensive/defensive, size and skating, you'll have different rankings for each of those guys. That said, I think all six guys are in that same conversation. Nemec, Clarke, Nikishin, Jiricek, Edvinsson, and Reinbacher seem to project quite highly. I think Buium, Levshunov, and Silayev are certainly in that group. Dickinson is pretty close as well.
I don't think Parekh or Yakemchuk are much further behind. If you called that the top 22, I don't think Yakemchuk would be out of place. In fact, I think you'd have a case for for him being ebtter than a few of those. However, multiple of those guys won't make it. It's just the way prospects work out. Similarly, it's probably a safe bet 1-2 of the 6 don't become top 4 d-men. Maybe a safer bet than 1 becoming a #1 d-man.
I'd be thrilled with coming away with one of them, because it means the Sharks staff decided they were worth the risk. Similarly, if the Sharks decide to pass on a Yakemchuk for Catton, Iginla, or Sennecke I'll be comfortable with that. That said, really don't think Eiserman is worth trading up for. Could be a 35 goal scorer who rounds out his game, and become the second best forward in the draft, but just feels like the risk be buts outweighs the boom potential. Same may be true for Yakemchuk or Parekh.