…Necroing aside, this isn’t strange at all considering that Gutter Runners are still from Clan Eshin regardless, even if they haven’t attained the rank of Assassin.
So an “Eshin One” would just be “One from Clan Eshin”, which a Gutter Runner is.
Although it is interesting that Saltzpyre apparently knows that there are different Skaven clans and can even differentiate between them, considering every other Witch Hunter will adamantly insist that Skaven don’t exist.
Which, they don’t. So stop talking about them already. They don’t exist.