If he is indeed 61 kg then his balance has to be increased. 170cm and 62kg along with a balance of 74, makes him just about stronger Shaun Wright-Phillips, considering he weighs more! I don't see what is wrong with a 75, especially considering how frail he is.
"If you are first you are first. If you are second, you are nothing" - Bill Shankly. "I guarantee fourth place" - Rafael Benitez.
If he really weights only 61kg BB surely needs to go up. I think smth about 76 is fair. (some people said 75, some other 77 so it should please both sides ) especially if it's like zuo says- that 9kg loss is approx. equal to 4 BB, because imo right now he feels ok in-game.