just to answer your intro, i remember this been suggested before.
i am not trying to be the party-pooper on this, but there is a lot more pressing issues i would have to even suggest this. even tho it may seem off topic, i'd suggest for the devs to start picking up their jobs first and not let the game go down in flames.
other than that, the idea itself isnt bad, but its also somewhat the point to not always get (or trade) the hero cards you desire but to make compromises and/or develop new strategies within the already limited environment that has been given to us.