It's not just you. Outside of the top 4, the Oilers might have the weakest prospect pool in the league. The top 4 is probably the best in the league though.
I picked Brossoit here but I'm far from sold on him. Slepyshev is a sleeper for me, I'd like to see how he plays the North American game first though.
I don't really agree that the Oilers pool is as bad as you say relative to other teams.
I don't really think people appreciate how talented Slepyshev is. His resume would make him one of the best prospects on many teams. You have a kid here who was a KHL regular at 17, has Captained the Russian U18 and U 20 teams, and who is coming off a breakout year. He also looked great at the Spengler. How does he compare with Andreas Athanasiou for example who is ranked at roughly the same spot on the Red Wing's prospect pool? Having watched Athanasiou in the OHL I'd take Slepyshev over him for sure.
If you go to the 5th prospect on many teams they will not have his potential. I'd say the same thing about Yakimov. These guys are very under rated since most people know nothing about them. How would Yakimov compare with Fredrick Gauthier for example. Gauthier is about #6 on the Leaf's list and they are said to have a top 5 prospect pool. Both are roughly the same age as well.
Guys like Chase and Platzer were later picks but really took off post draft. They may not be high end talents but both could be useful NHL'ers. And few teams would have high end talents outside of their first few prospects.
Laleggia on the other hand is extremely talented. He also has a spectacular college resume. His main issue is that he is not that big. But 'd take him over Mike Reilly who was this year's Justin Schultz.
Davidson may not be an exciting name but he probably passed Marincin on the Oilers depth chart before Marty was traded. He is very close to being NHL ready. He probably would never be anything more than a bottom pairing defenseman but for a prospect that in itself would be a significant accomplishment since the vast majority of even the higher ranked prospects on most teams never make it.
No question that the Oilers prospect pool drops off after #4 but their top 4 is absolutely exceptional. The other thing I like about the current prospect pool is that it suits the teams needs. They have Nurse and Reinhart as potential impact defenders which they certainly need. Laleggia is a long shot but could at some point be pp specialist.
They don't really need small skilled forwards. Going forward what will be a key is if they can get guys like Pitlick, Chase, Khaira, Yakimov, Moroz, and Kessy to fill out some of the bottom 4-5 forwards spots for cheap money. If two or three of those guys can do so it would be huge in terms of cap management down the line.