I remember that book. He also wrote The Silver Crown.
Nym is mentioned in the Boy's speech in Henry V:
As young as I am, I have observed these three swashers. I am boy to all three; but all three, though they would serve me, could not be man to me; for indeed three such antics do not amount to a man. For Bardolph, he is white-livered and red-faced; by the means whereof 'a faces it out, but fights not. For Pistol, he hath a killing tongue and a quiet sword; by the means whereof 'a breaks word and keeps whole weapons. For Nym, he hath heard that men of few words are the best men, and therefore he scorns to say his prayers, lest 'a should be thought a coward; but his few bad words are matched with as few good deeds, for 'a never broke any man's head but his own, and that was against a post when he was drunk. They will steal anything, and call it purchase. Bardolph stole a lute-case, bore it twelve leagues, and sold it for three halfpence. Nym and Bardolph are sworn brothers in filching, and in Calais they stole a fire-shovel. I knew by that piece of service the men would carry coals. They would have me as familiar with men's pockets as their gloves or handkerchers; which makes much against my manhood, if I should take from another's pocket to put into mine; for it is plain pocketing up of wrongs. I must leave them and seek some better service. Their villainy goes against my weak stomach, and therefore I must cast it up.
(I know this as it's Petrova's m'audition speech in Ballet Shoes)