was this thought of because they are both pure shooters?
I think the comparison of Sprong & Perreault is not a good one. Sprong was always a pretty one dimensional prospect, although it was a pretty good dimension (speed & scoring ability). Perreault is a lot more toolsy of a prospect. Perreault is more physical, a much better playmaker, has at least as good a shot and was one of the best skaters in the CHL, even if he didn't always show it off.
The big question with Perreault is defense, he clearly has the tools to be a top 6 winger. Sarnia had a brutal team this year and many games they were simply overmatched and Perreault seemed to lose interest, or at least he has been characterized that way. I didn't see enough of him to make a judgement but I recommend watching the 2020 CHL Top Prospects game. He had a nice showing there amongst his elite peers in the CHL. High ceiling and low floor is the way most scouts seem to be categorizing him.
I guess we'll see. I think in the right system, he becomes a very good NHL player.