Completely agree. I think the only reason you'd want to trade Nuge is if he can bring back a significantly better dman than Eberle or Yak (i.e. a top 20-30 D in the league signed long term). I think the chance of a D like that becoming available is slim, and therefore we'd be better off trading Eberle or Yak with an add for a D who isn't quite that good. I'd love to keep both Eberle and Yak also, but I think one of them will probably have to go eventually unless we are somehow able to get Yak signed long-term at something around 4 mil (assuming he keeps meshing with McDavid or even with Draisaitl and Hall and can be a 50-60 point guy).
Either way I think people are just being a little impatient with the situation. I understand that people want to see our D get better, but in reality they aren't that far off if we can add another very good top 4 D. Klefbom and Nurse both look to be trending towards top pairing D in time, and Sekera after a rough start has really settled down and is looking like a good #3. If everyone would just take a step back and look at the big picture, they'd realize that if Nurse and Klefbom develop into what we think they can, then having 3 centres who may very well all be #1 quality centres (or at least top 30 in the NHL) will be extremely valuable to this team.
I think you also need to look at the play styles of those 3 players and their projections. McDavid gives you the elite generational offence who can drive the play, create numerous chances off the rush, creates turn over after turn over in the neutral zone, and can be good in his own zone. Draisaitl gives you a guy who should be a beast in the face-off circle who gives us a dominant player that can protect the puck and cycle down low, has elite vision and passing, and a very good 2-way game when it comes to breaking up plays. Then you have RNH who while he may never be a stud on the faceoff, he has at least improved to the point where he's not a total liability anymore, and he plays such a smart game, is good on the forecheck and pressuring in the offensive zones, creates lots of turnovers by picking off passes and stripping players, and then just has above average-to good skating, shooting, and playmaking. Being able to have 3 different guys who play different styles at centre, but who all have or will have strong 2-way games will make this team much stronger up front than keeping both Eberle and Yak will.