On the D side you already said most of it IMO.
Even if the best swiss players of the last 10 years are defensemen, the depth just isn't as good as on offense. The strong generations born 77-83 are finally history, 85-86 won't be around for too long, and from the younger ones the arguably 6 best are in NA. There just isn't enough talent around to fully compensate.
From ZSC beside Geering and Sutter, I think Marti would be a more proven option for Fischer over Baltisperger. Even if the latter one has finally taken a little step forward, but Im not sure his technical skills and decisionmaking would be good enough (yet?). Would have to keep his game very simple... Oliver Keller style simpel.
Some positive things about the state of defense.
Having watched the resurrection of Mirco Müller the last few games was really satisfying. He still does underplay his talent big way. Which is very understandable, regarding the hole, he's crawling out, especially the mental one. He really should have come over to Europe for 1 or 2 years, to grow into a big role step by step, and forming out his offensive game. I really hope, it won't cost him, as he got tremendous pure tools, but so far had no clue how to use them properly in the NHL. An outstandingly shifty and quick skater for his size, quick hands, good passing technique, improving vision and timing, has developed a hard one-timer/slapper, which he could use from time to time, and finally starting to use his body and marking his zone. He starts using some of them a bit, but come PO time soon, it's probably not the right time to discover terra incognita in a too risky manner. He looked like a very happy man yesterday after the Devils game. New team, new luck, very good preseason, solid start to the season, fading a bit, then kept on a short leash, lost in the shadows of his compatriot teammate and his sister's olympic performance, getting back into the team, put in the doghouse for ages and comes out and plays like a top4 defensman and now gets the minutes of one too. What a rollercoaster!
And I really hope, we're going to see Noah Delemont at the U-18 WC, Im super excited to see him play. His play-off performance from the Novize Elite league must have been outstanding from what I heard.