Muster/Quartermaster/Minibot made Paladins not suck.
MC made Paladins OP.
Shaman need a more efficient way to interact with their hero power & overload to become good.
I saw 1 card suggestion that would be pretty sick, and probably be equiv to MC for Shaman:
It's a 9 mana play which makes it slow but the tempo swing would be crazy. Shaman need cards that use your Overload. Right now the Overload mechanic is not being fully utilized and Blizzard doesn't even cost cards appropriately when using it.
Note: There may be arguments against this saying how Blizzard doesn't like players affecting other players decks/mana, but think of this card as a Loatheb/Mana Wraith/Saboteur/etc. It's just stronger and class specific.
Overload sounds good in theory - get strong minions out a turn early - but this game is about Tempo and you get punished extremely hard.
Lets look at Totem Golem, for example: It's a 3/4 for 2+1. Same as a spider tank except you can play it turn 2. But then you only have 2 mana on turn 3.
Compare to Minibot: 2/2 for 2 with Divine shield making it a 4/2 for 2. It trades evenly against Totem Golem and doesn't fuck up your tempo.
Overload is valued too highly. For Totem Golem to be correct, it needs to trade with a 4 mana minion, not a 2 mana minion. It should be 3/5 or 4/4 at worse. Even Blackwing Tech is a 3/5 for 3 (assuming you meet the condition) and it's a neutral card!
Shaman will forever be fucked until Overload is treated fairly.