It's reasonable on a casual level, as I had a nice fun match using my True Dracos. It's nowhere near something like Altergeists, but definitely gets over 40goodcards.dek at times. It has some neat tricks, but it clearly can't handle something as simple as a Fossil Dyna. Another issue is many of the cards just have no synergy. And I don't mean Red-Eyes Darkness Metal Dragon(which at least helps the deck, despite having no real ties to the archtype besides being a remake of Red-Eyes Black Metal Dragon).
I have been working on a variation of the cards, with Scarlet-Eyes Shadow Dragon. I didn't notice that Red Dragon Archfiend was tied to the words Scarlet at any point, though it's clear that the monster is a remix of Red-Eyes Black Dragon and Blue-Eyes White Dragon in multiple ways. It's far more based upon Red-Eyes' design as well as upgrades, where the stats and purpose of being used by the rival is BEWD.