This won't work at all. The crux of the entire deck is the card advantage gained by Echos and, to a lesser extent, Mad Scientist + Duplicate. Midrange Shaman is a thing, and may still find greater success, but it won't do it with poor imitations of decks from other classes.
crusher shaman has been a thing before, and runs on some similar concepts to the last boss deck, I think we can convert it into a new version of crusher shaman, and bring that back into the shaman decks. I think it's possible, and we should give it a chance.
The strength of the deck also comes from battlecries, like BGH / MCT / Healbot, and the possibility to echo the most useful minions for the matchup (i.e. echo BGH against handlock, or water elemental against warrior, MCT vs paladin etc).
It goes well beyond the deathrattles.
It's not a strategy you can replicate in shaman. You are better off with starting something from scrap.