I disagree with your assessment that he has no offensive game.
While he did light it up at the start of the season then died off, he still showed that he has offense in him.
He played most of his 63 games last year in the KHL as a 17 year old.
The tools are there.
He actually models his game on Hedman and watches lots of video of him.
He has one of the all time greats coaching him, the Professor, Igor Larionov.
And I know it took him 63 games however he broke the scoring record for an under 18 player in the KHL.
For sure you can't project his offense like you can with Buium or Levshunov, however he certainly can develop his offensive skills in the next couple of years while being coached by Larionov.