This is just semantics, but all right. There are 15 different ships so far in ED. Which of these, besides the Viper, are in your opinion fighters? I'm guessing none. There is a pretty clear progression ladder in trade vessels, and from a game designers POV there should be the same for fighters.
Pure fighters: Eagle and Viper.
No, I don't think there should be a ''pretty clear progression ladder'' and I think that it's pretty obvious that it shouldn't from ''the game designers POV'' too. Or do you think FD nerfed the Python by mistake? This isn't supposed to be a game where we ''grind'' until we have the best ship and then go into ''endgame'' where we compete in e-peen contests.
We're getting two heavier combat ships and one light-ish. Hopefully, the heavier combat ships will still have trouble outmanuevering and killing Vipers, but they should have other qualities which makes them attractive.