THat's a big one, but I certainly enjoy that kind of responses, thanks.
That's not an easy question, since, if we think of it that way, the hockey IQ is an umbrella term that covers a lot of stuff: creativity, reliability, vision, timing, decision making, character, consistency etc. For example, Likhachyov: he has always been creative and this season more-or-less consistent, but not sure if that would make him a high-IQ guy in my eyes. Still, if you would like me to try to group them somehow, I'll try, but I'm not sure it won't cause a confusion, I'll use my list though:
Aside from Zlodeyev, in the "great" category I'd have Askarov, Pashin, Beryozkin and, maybe, Alalykin and Chizhikov (that was probably unexpected to everyone, but I like what he does).
In the "good" I'd probably place Groshev, Trineyev, Sokolov, Kuznetsov, Tsyplakov, Sheshin, maybe Shashkov and Marushev.
In the "weak" group (actually I'd prefer to use "questionable", since labeling them as "weak" already at this point of their careers requires them to do something really dumb) I'd place Mukhamadullin, Tyutnev, Gutik, Likhachyov, Steklov, Galenyuk, Tyuvilin, Gordin, Akhtyamov, Didkovskiy.
As for others I'd say "average" would be appropriate, but again, those things should be viewed in details, this is a very approximate grouping, as for different players in the same group this hockey IQ evaluation might mean totally different things.
Zlodeyev's reason for the lack of offensive production is the WJAC - while he was on the middle-six line, it didn't exactly click, so only 1 A in 6 games (although I'm pretty sure one more assist was "stolen" from him by stats guys). In other tournaments he did better: 2G+1A in 4 games at the 5Nations, 1G+2A in 5 games at the Hlinka's.
Well, every player of the U18 NT could've had another opportunity to show what they got at the U18 WJC stage, particularly I think everyone wanted to see Ovchinnikov, but maybe Trineyev woud've benefited from that (as he wasn't there at the WJAC) and maybe even Agapov. As for guys like Beryozkin and other 2001 borns, they lost an opportunity to showcase themselves both at the 4 Nations and, what might be even more important, at the Sochi U20 camp, as there would be a lot of scouts there and previous experience shows that a lot of guys, who look good there, get selected. But again, maybe they would dissapoint us, we will never know now.
Gavrikov was definitely better, he entered the 2015 draft as the WJC best defenseman. Galenyuk is interesting in terms of natural physical giftedness and improved skating, so I think somekind of the offensive production could be there later on too, but he still is a bit of error prone and can take a bad penalty from time to time, so I'm not high about his hockey IQ. With Pylenkov, it is a bit of other way: I don't see offensive potential, but he looked pretty reliable at D... but only in the second half of the season, as even back at the CAN/RUS Series I was heavily criticizing for positional errors, therfore it's not easy to make a judgment on which is his true form. But anyway, I think Gavrikov is just in a different tier.
If Askarov wasn't so good, Skotnikov would've be a U18 NT full-time starter in 2018/19, so he would've made some more impression back then, as for this season, I don't think so, maybe could get a game at the 4nations in November, but that's all. As for the "if it was not for size", it's kind of a huge "if", but if we imagine that he is an inch or two taller, I think third or even late second round (if a draft is as weak at goalie depth as last year) would be a realistic expectation, imo.
A lot of stuff, but I hope I kind of answered your questions, but even if I didn't, feel free to ask more - I'll gladly continue our discussion.