Small, random questions about RotE that still bother you (spoilers all RotE books)

[Farseer]

I'm kind of thinking the "other one" that was broken was someone else they had tried to train as an assassin but who had failed the task(s).

I still believe this "other one" who was broken was Chivalry (link to post #4 , my discussion on page one of this thread). To add weight to my previous reasonings, in Chapter Seven of AA "An Assignment", Chade is talking to Fitz about Chiv after he has died. Fitz has asked Chade how he would know anything of Chivalry and Chade replies:

"I've known him all of his life. I've ... worked with him. Many times. Hand in glove as the saying goes."

Chade and Fitz then go on to discuss the relationship between diplomacy and assassinations, suggesting that Chade and Chivalry worked closely together, often in a similar manner in which Chade and Fitz did re the diplomacy road that Fitz chose when it came to Lady Grace, rather than deciding to remove her from the scene, was something that ended up being more than a little Chivalry-like. In fact, Chivalry himself had also previously spoken of the watchtowers as being his "best and dearest jewels" during a diplomatic visit to a lesser keep somewhere (see a discussion with Burrich in AA, Chapter Four, "Apprenticeship").

While it is very doubtful that Chivalry was ever Chade's true "apprentice" as such, particularly as he was the heir to the throne after all, it is highly likely that Chade taught Chivalry much of what was taught to Fitz and even later, Dutiful. Being a bastard, Fitz could be apprenticed by Chade but Chivalry and Dutiful could only ever have been officially "mentored"...but they amount to pretty much the same thing in my opinion? Chade would have had the same role in all of their lives, despite the difference in labelling?