I've played around with this too. But it seems too slow, especially with the current dominance of rush decks. I feel like bleeding speed is just crushing even the combo decks atm. Except maybe that mermaid life drain mess. 😧
Like Mbuna, I don't think this idea can work -- at least not as a focus for a deck. As described, it requires three steps (and at least three cards): killing an enemy, bringing it to your discard pile, and resurrecting it. On the average, you will not get a three specific card combo until about your eighth turn -- which is really too slow. But even if you do make it happen, why do you think an enemy minion will be more effective with your deck than a friendly minion you choose yourself?
That said, certain combos using this idea can be useful support for a deck that has another primary focus. For instance, gargantula (jungle) can be used to bring a good minion directly from your opponent's hand to your discard pile, where rebirth (forest) can raise it. This maneuver rarely wins games, but since both gargantula and rebirth are otherwise useful, they are worthwhile additions to many decks even without considering the combo.