I remember setting out to train dragons on a Pokemon Pokemon Blue playthrough. Now because there is only one line of Pokemon that actually has the dragon typing, and it's a late game Pokemon, and I wasn't using a cheating device, I couldn't complete the game with actual monotype challenge or even a Dragonite solo run, so instead I made a theme of team of dragon and dragon-inspired Pokemon, including Charizard, Gyarados etc, in addition to using all stages of the Dragonite line, essentially I did what Lance did.
I'm not positive about what Pokemon occupied the 6th and final slot.
Nidoking or Nidoqueen would have been a the best choicebecause they are cool, formidable dinosaur-like creatures that could count as psuedo dragons, and you can get Nidorans very early game before you have any badges near Viridian city, and they have really wide move pools for coverage and a ground typing to fortified me further against the electricity that Charizard and Gyarados were weak to. I kinda doubt younger me had enough strategy to do this though though.
I might have ended doing something like put an Aerodactyl on the team, that I thought looked cooler, but would have helped me far less lol. At least I had a nice time though :)