In Darmok, the Tamarians stranded the captains on the planet and jammed communications. Whether they have a specialist or not, they wouldn’t have been able to help Picard, and there wasn’t enough context in the ship-to-ship communication logs to figure out their meme-speak anyway. Data and Troi do still figure out pretty quickly that it’s a meme-based language, but, again, the lack of context means they don’t get far.