Murky vs Malfurion
Laning against Malfurion is a piece of cake for Murky. He would not be able to kill Malf due to his heals but could certainly push minions up to the gate. Just need to watch out for Malfurions root which is easily dodged. Malfurion will typically use his root to clear Murky's minions so do not stand in the midst of them.
Fish Tank does not Murky with Malfurion but with slime build he can out damage Malfurion' heals. It does take a while though. Remember that Fish Tank prevents all damage sources. So you can attack Malfurion while his team member beats on Murky with physical damage and Murky will be fine.