Fallout should really get more into the micro mutations that the radiation has caused. Like both with already mutated creatures and non-obvious ones.

Psykers, Night-kin, tunnelers and multiple other variants of mutated things exist so why can’t humans with other slight mutations? We know that radiation and FEV have affected how things have evolved, so it’d be really easy to say that these tribes or factions can do this cause they are slightly mutated to better fit their environment.

Perhaps Mojave people that live in very high areas have just noticeably long limbs due to all the climbing. Perhaps those who live in dark areas have larger pupils and borderline night vision. Perhaps rando NPCs that just mention having webbed hands cause their families live around water.

Like I’m not saying a bunch of new mutants or factions but just like humans who are more obviously slightly mutated.