I run into bad Murky more than Aba period.
You don't understand what I mean when I say 4 Protect 1 but it's more of a Dota thing (maybe LoL too?) where 4 players have to hold the lanes and match for X amount of time before a carry they've been baby sitting in safe lane or jungle finishes farming, gets a bunch of big ticket items, comes online and starts wrecking the other team.
I'm not saying you literally have to protect Murky or Abathur, what I'm saying sometimes when you're playing with either of those heroes it feels like the strain of that without the reward. Like you're down a hero that never comes online.
And by sustain I mean literally not feeding every time he spawns and runs into anything. Teamfights, forts, lone heroes, Mercs, minions...like a lemming, over and over and over and over. There's being a continual distraction or annoyance, preventing them from completing an objective and then there's being a lemming, or worse just camping a lane with March like it's Alpha Murky.