Text:
Raider, Ally, Bastard
Limited Response: After a card is discarded from a player's deck, kneel Euron's Mongrel or kneel a Warship location to choose and discard 1 copy of that card from play. (Limit 1 limited response per round.)
The FAQ reads :
(4.8) Card Title
A player may only include up to 3 copies of a
card with the same title in his or her draw deck
regardless of card type.
The CS rules reads :
• Your House deck must contain at least 60 cards,
and may not contain more than three copies of a
card.
I'd say that there was a need for FAQ clarification because the very definition of "a copy" means exactly the same card, Title, type and all. But I could be confused since English is not my mother tongue.
So, while I would say that Euron's Mongrel cannot discard a copy of a card regardless of the card type/text (for instance Grey wind character if the Grey Wind attachement is discarded from the deck) - I'm not 100% sure either.