Tage curved a lot harder, a lot faster than Riley did, especially with the benefit of hind-sight and what he has become now but he never had that "6'5 winger who can score goals" ceiling that Riley displayed. Hard to say what call I would make if I was them at the time, and I always liked Tage. Staying in high school likely jolted Tufte's draft stock but probably hurt his development in the long-run
They were (still are) both projects for sure, but I think your explanation, particularly the ceiling claim is a scouting issue indicative of how a guy like Tufte goes far too high in the draft. It's like scouts fall in love with the tropes about some players - "6'5 winger who can score goals" - and actually ignore the evidence about the player and whether the trope is appropriate for that player or inappropriate for a similar prospect. There was as much, if not more,
worthwhile information for at minimum that label to also apply to Tage if it applied to Tufte.
At 14/15/16, sure Tufte was better than Thompson, but Thompson was incrementally improving, and improved a lot as a 17/18 year old, whereas Tufte had seemingly plateaued and/or he wasn't as good as one hoped as a youngster as he couldn't produce against better competition and never got better.
Heading into their draft, Thompson had just scored 14 goals as an NCAA freshman while averaging 0.89 PPG. He was second on his team in scoring, behind another freshman (Letunov) who was 20 months older than him.
Conversely, Tufte had a monster high school season (though another guy on Blaine put up the same exact point totals and was then almost always scratched for Minnesota before leaving hockey all together), but only produced 0.52 PPG in the USHL that year and scored less goals-per-game in the USHL than Tage did in the NCAA. That's not to say scouts should just throw out high school performance because it's high school hockey, but with Tufte, there was
plenty of evidence countering that production to indeed throw it out or discount it. And there was plenty of evidence to think of Tage as a "6'5 winger who can score goals" at that point if that label still applied to Tufte.
My point isn't that Thompson was a slam dunk pick over Tufte as he wasn't. It's about falling in love with some aspect of a prospect and ignoring the mounting evidence showing the reason for that love is a mirage and/or that a similar prospect is a better version of the original prospect that one's fallen for. There were signs that Tage was the better prospect at the time of the draft, but the signs were ignored. And it's not really about hindsight as the signs were there during their draft seasons.