Dear Anime Nerd, Welcome to the board !
I am sorry you could not make your brother think, or really honestly look at his position, I had the same problem with my nephew.
I think you made the mistake of letting him side track you, it seems that way, as you relay the conversation. Our very own "Black Sheep" points this out many times.
You : "There is no way Jesus would have chosen them in 1919"
Saul: "They are imperfect men, and the light keeps getting brighter"
The above answer from Saul is irrelevant to the question, you must return to the question,straight away, not discuss the imperfections or bright light just repeat:
"There is no way Jesus would have chosen them in 1919"
I only outline this for the benefit of others, and just in case you get the chance to repeat the exercise. Just stick to the 1919 "choosing", they can offer no proof.
As I said above, I put this very question to my Elder Nephew, but in a letter to which he has not responded.
I really do not know what level of Cognitive Dissonance and downright burying ones head in the sand one has to use to not see the problem with 1919, and the ramifications, if the GB cannot prove their provenance by this choosing, they have no authority, and no reason to sit on high in Brooklyn ruling over 7 million mind-controlled JW's.
But having tried to get this over, with no success to several long term JW's I realise that to actually get them to reason, and to honestly examine their beliefs is well nigh impossible.
Once something tips them over the edge, then you get a chance, but all the while they do not want to see, they will remain blind.