Quoting: Eddy
That trade is fair and works for both teams needs. Compher and McCann are similar in value and Murray can get a second plus a prospect easily. Timmins is a good player/prospect but not a home run either and with what Avs have on D right now and in next few years they aren`t going to miss him. The second for an Avs team in win now mode too isn`t a big deal either. They have more than enough in the pipeline and still a decent amount of draft capital. Simon is a depth throw in good fringe player for them too. Avs get a franchise goalie entering his prime. I would say the Avs slightly win this trade because they get a true #1 and only have to give up things they won`t really miss. Pens get their 3C right shot and a young cheap dman for their third pair.
There's a few fallacies in your post, highlighted in bold.
First of all Timmins is absolutely not a prospect we can just cast awa without missing. RHD is our shallowest position organisationally and Timmins is our best chance at replacing Johnson at 2RHD long-term. The fact that he's still on an ELC and likely to be on a cheap bridge deal after that is extremely valuable too. Draft capital like 2nd round pick is fairly expendable, but we need to be mindful of hitting on some of those picks so that we can have players on ELC's in 2023 onwards.
Secondly, if Murray was a "true" #1 and franchise goalie then Pittsburgh wouldn't be trading him. The goalie market is pretty saturated this offseason, and we're not really THAT much in need of a goalie change, so we'd only do a trade like this if it's a cheap acquisition.
As for McCann, he was a healthy scratch in the playoffs which isn't a good look at all. He's maybe like the 10th option at 3C I'd be looking at this offseason behind a long list of better alternatives (eg. Bonino, Danault, Domi, Stastny, Eakin, Haula, etc etc)
If you remove Timmins this trade might work, but even then it depends on what Murray is asking for contract wise. If you want a bit more then just remove Simon and add a B/C prospect on Avs side (not Timmins/Bowers/Kaut/Annunen/Byram/Newhook). Or just do a deal around Murray for Compher/Jost/pick.