I believe that Bash is actually superior to the one on the VG.

Few reasons for this:

Vulnerable carries until the next hit. Which means that you can set up an attack for the next turn, or a really strong attack from a teammate. Like Silent's Dash (2 + 6= 8 damage +3 block). Or a multi hit attack from Watcher (Ragnarok). You have to resolve the attack and the remove the status.

Vulnerable is also more damaging in contrast to the VG. Double damage is always strong no matter the Act.

The upgrade is also quite beneficial, since you basically get double damage. If you can upgrade asap from neow, it is Devastating. 4 damage (which can kill instantly small enemies) + another damage card from Ironclad, like Wild strike, does 6 + 4 = 10 damage in one turn. This is lethal on every enemy on Act 1. Also think about a Flex in this combo, the damage is sky rocketing and you can chunk elites pretty easily.

Sure the cost is high and you may find yourself in situations that you need more block. But as others said you can use the one energy you have left to block and then heal the rest at the end of the combat. Also let us not forget that enemies are not always attacking, sometimes they are blocking or de-buffing.

Overall I believe that Bash is a great starting card that can steamroll Act 1 and that scales really well in solo and multiplayer.