I'm currently halfway through A Storm of Swords. Dany has acquired her Unsullied and is trying to amass a greater army before heading over to Westeros. She is trying to convince The Second Sons and Mero to join her, but Jorah and Arstan Whitebeard don't think it's a good idea.
But when Mero was gone, Arstan Whitebeard said, "That one has an evil reputation, even in Westeros. Do not be misled by his manner, Your Grace. He will drink three toasts to your health tonight, and rape you on the morrow."
"The old man's right for once," Ser Jorah said. "The Second Sons are an old company, and not without valor, but under Mero they've turned near as bad as the Brave Companions..."
How does Ser Jorah know about the Brave Companions?
This site says that the Brave Companions were only brought to Westeros by Lord Tywin during the War of the Five Kings, which is currently on-going. So how did Ser Jorah find out about them and their reputation?
If Ser Jorah has heard about the Brave Companions in one of the port towns they've stopped at, how is it that word has not spread across the water that Daenerys is amassing this great army to come fight for the throne? She hasn't really been mentioned at all in Westeros, except in passing when people talk about how Dany and Viserys fled during Robert's Rebellion.