The only time fire/fighting as a type combo made sense was gen 4 since it gave Infernape some form of advantage over Empoleon. Although Blaziken was the original, so I think both of them are excusable. Gen 5 was just
for making it Fire/Fight a 3rd time in a row.
Oh, and making a tournament on Pokemon Showdown in itself is pretty easy. I just am not sure how to go about the organization and promotion aspects.