Nino and strome are par for the course, 5th OA isn't likely to produce a superstar that often and both of them became solid nhlers, which is pretty good, although they didn't accomplish it for the isles. Neither of them ever had realistic superstar potential, they turned out ok. Nino has six 20 goal seasons and Strome has become a 50 pt player, at 5th you can hope to get a star but its much more likely you end up with something like that
Ho sang was a massive boom /bust pick and many people projected him as a star or a guy who would be in Europe in 5 years - the latter were right.
The others are misses, I don't think it's the isles system, you just miss on picks sometimes. Look at NYR or mtl , their track records are just as bad or worse for picking 1st rounders, nyr had 4 top 10 picks in a row including a very hyped #1 OA that didn't live up , it could be situation, on the players, or a combination of both which is likely. They haven't been "good" at drafting but they've been worse at managing assets imo