Why draft a top pick for the floor of a "big guy who is good at D?" Plenty of other picks to do that with, seems like odd logic IMO.
Buium is a striker.
His play in his own zone is efficient, not super physical but comes out the wall/battle with the puck already knowing what he's going to do next, kinda like the way Keith played in his own zone. He'll still pin a guy when needed but his quick decision making allows him to take the best approach in the moment. Definitely the opposite of the big reach using his body type D.
As per offense, Fox might be a decent comp? But, to be more detailed, it's again his decision making on the fly. Lots of shifts he's conservative when it's called for, he only cheats when it's there. He's not an offensive D that tries highlight silliness every shift like a lot of O-minded D in juniors. If a guy gets the puck off him when Buium cheats there's someone behind him already as insurance. When he goes up on the cycle he's a huge threat because he plays like a forward. He can power to the net, wrap around on you, he can stand still in a wall battle when pinned and make a sick pass behind him, has a hell of a cut too. Lots of plays in his book.
Really, the big thing is how he executed his game at his age against the NCAA. Denver basically went back with a very similar roster of a few parts swapped plus Buium. They put up 52 more goals this season than last, raised the + column of the whole roster, won the title and people who followed Denver give Buium credit for QB'ing the team in that direction.
As a Hawks fan I think getting the team a high IQ offensive catalyst would be huge.