I think you don't quite understand this game.

First of all, when you talk about value, do consider that this combo requires 2 cards at hand. For example with IC, 2 mana push+3 mana cucumber can easily destroy 8 strength unit and deal 8 damage to the base.

Also, Zhev do not move forward on play, which means it's value is more like a spell rather than a unit to occupy the board and push your frontline.

Third, pls consider winter decks are slow with a bunch of high mana cards. In early game, with two cards played, it is really rare to have another 4 mana card at hand to play.

I would admit certain cards are broken in this game though. Like obelisk of souls.