The Striderpostor healers are one of the variations the Striderpostors, being the weakest ones if we talk about physical strenght, but they're the smartest ones too.
Why do they have those properties? They arent made as fighters but as supporters, healing damaged impostors or even other Striderpostors. They clearly need intelligence in order to help out their allies, thus making their intelligence above others of their kind.
Even if they're weaker than others, does not mean they are useless in combat. They're still quite strong, but clearly another variations like the gunners and Roufostors have more utility in that aspect.