Personally Broken Steel I gave the nickname years ago to 'Broken Balance' because of the new top tier ghouls, super mutant and radscorpion on top of the perk Almost Perfect, broke any chance of balance what so ever in the game, for amusing, if not irritating effect. If there is anything that will likely kill the Merchants, it is most likely what will cause their death later in the game. They can take on a Deathclaw normally, (unless) TTW changed this. They dish out an insane amount of damage, unless TTW changes this, while having an health pool of a god. To be honest, it's more of a problem with Albino Radscorpions.
