Geez, You want to merc-camp the Glow too?
This feature may be interesting. But It should have a disadvantage too, since human charters can't even reach few places without getting damaged.
why exactly? it's not like the player is immune. There is no need for a disadvantage to fix a bug.
Because it would be too much overpowered, player won't use human mercs anymore. A disadvantage might be the price of ghoul and mutie mercs: they can reach radiated spots without any damage but their price is higher. Making something like that it's better, more balanced.