His implication was that rattata and spearow were reserves, since they're unused, even though he has 6 pokemon total.
As an aside, fwiw I did attempt a pokemon gold nuzlocke... after accidentally killing my first pokemon on the route all the way up to the first gym, I adopted a personal clause to take the first pokemon I could catch on that route. Then even after that bit of cheating I wound up nearly wiping early due to mis-remembering gym leader levels. Around the time I lost my lucky heracross I was saying "Okay **** this challenge, I lost now to blast through the rest of the game"
Nuzlocke's are not for me. Especially given no audience to keep me from cheating :x
Yeah most of the people I know in Real life don't like nuzlockes.