Untouchable : None.
Nobody looks like a McDavid, let alone a Stutzle. I don't think anybody is untouchable.
I've said for a year now that Durzi does 90% now of what we hope Clarke's ultimate upside will be. So, if I can get a legit top tier player for Clarke then I'm moving him. Byfield played his best game as a King last night but he's not untouchable. I don't know if that is what he ultimately becomes or that's fools gold and he's move of a 0.5 PPG guy.
I overall agree with your slotting of players and would definitely move Iafallo to free up some cap space and plug JAD into his spot. Somehow the light bulb has come on for JAD in the latest call-up. With Moore getting extended, the Kings are need to pick between keeping Iafallo and Arvy. It doesn't make sense to pay 2nd line money to have someone play on the 3rd line.
Also, what about Bjornfot? He's never impressed me (I'm in the minority on this one) and he's going to be transitioning from a guy with 100+ NHL games by 20 into a guy who's played at the NHL level but looks to just be another guy.
I think Byfield is untouchable for me because of all the reasons we drafted him. You're gambling on potential there, with all the basic physical traits that could make him supremely dominant. I agree that if the right deal came along, id move him, but the right deal "for me" just isnt really something i would expect to happen. you're not getting a top tier, young, dominant center back for Byfield as the centerpiece of the package. Even if you could find a team to make that trade, you'd be sending considerable assets the other way on top of Byfield. Let the kid grow and trust that the process will work.
Which brings me to Clarke. I think we have prospects in the pipeline, and a bit of a redundancy with Durzi, that Clarke does come off as slightly more expendable to me. I think Clarke will probably wind up being the best player out of all the offensive defensemen, but with a glaring hole at LD, im more willing to trade clarke for the right fit at LD.
As for Bjornfot... who knows. I have seen enough to know why the Kings drafted him. He's flashed some offensive instincts, but the consistency and decisiveness has lacked. And that's to be expected. He's young. So, id say im impressed with what he could be, but like a lot of these young prospects, he's got a ways to go.
With Durzi, he does bring some good offensive instincts to the table, but he's not elite (clarke could be), and i think that's a significant point to consider, because Durzi needs to minimize his mistakes. last night, he made a bad read, trying to go forward as the last guy back to make a play on a puck he was never likely to win anyways. the player went by him and scored. I think he brings good offense to a team that desperately needed it on the back end, but i still find myself wondering if this team would be better off with somebody more reliable, because right now, id ideally have him playing bottom pair and PP. Clarke could be Fiala, where he's so good on offense, the team ha sto adjust to his game a bit. Durzi isnt at that level (and clarke may not get there either), so you'd like to see him become more reliable and predictable on D to offer a more complete package.
I want to make one last point with respect to plugging guys into top 6 roles for guys like Iaffalo, or Arvidsson, or even Moore to some degree. These more veteran players have demonstrated that they can be defensively reliable, fairly consistent, and still produce. JAD has looked great the past month or so, but he doenst have the track record. Kupari has shown improvement, but he doesnt have the track record. I think it's a bad idea to simply start penciling these guys in for top 6 roles until theyve shown they can do what were seeing this season, over the course of an entire season. And both JAD and Kupari have not shown enough production, like Kaliyev has, to guarantee they ever become more than bottom 6 guys. So Arvidsson, Iaffalo, Moore... none of those guys are expendable to me. I might move one of them if push comes to shove, but it's not because i believe one of the younger guys can just plug right in. It would be because i think the loss of losing one of them would be outweighed by the gain of whoever it is we trade for.