I do not think he will be a huge offensive talent, and defensively, I am not entirely convinced he is a guaranteed top pairing guy. In a draft this deep up top, that does not equate to a guaranteed top 10 pick.
However, since the top of the draft is heavy on wingers, a team who needs defense may prefer him over a higher risk, higher upside guy like Rossi, Holtz or Perfetti. I do not see why he would be ranked over Drysdale at this point though; Drysdale is at another level compared to Sanderson and is a far more rare RD with an all-around game.
I mean, just projecting the draft, Sanderson will likely be gone before 8. He's an all-world skater who excels at transition defense, one of the most sought after traits in the way the league is trending. High-defensive IQ, which great gap control and elite skating is a guy who eats 25 minutes a game. May not be 1st PP, but likely top ES guy, top PK guy and a possible 2nd unit PP guy. That's a Slavin type player usage wise. I'm not sold on Drysdale, he has more flash but his defensive game is inconsistent, and I don't think his offensive ability is as high-end as people think. Outside of being left-sided, Sanderson is exactly what the Leafs D would need, and many other teams are chasing that guy. So many people point to Quinn Hughes for Drysdale, when he also has a ton in common with someone like Jake Bean.
I'd also say I don't think this draft is extremely deep up-top. If it was that deep up-top someone would have seriously challenged Lafreniere for 1OA. Who is a good prospect, but probably outside the top 5 when it comes to best draft-prospects over the last 10 years (McDavid, Matthews, Eichel, Dahlin, and MacKinnon), with arguments for a few more (Jones, Laine, Hughes, Kakko), It's above-average to good up top, but I'd put it behind 2015 and 2016 of draft years recently.