Here is the relevant FAQ
The cards Herders of Kinos, Merchant Fleet, Servants of
Rogoth, Tyrean Warriors, and Pilgrims of Enlir should all
read: "This is a Horde card. X is equal to the number of
Horde cards you have in play in this column."
The card High Priest of Rogoth should read: "This is a
Horde card. When you play this card, you may draw up to
two cards. X is equal to the number of Horde cards you
have in play in this column."
I don't have the cards handy but I think it said "horde cards in play" which was really powerful. That is what sent me searching for errata. The cards were supposed to say horde cards in this column. For example, with 3 horde cards in one column X = 3.