Red Ramp decks really struggle with maintaining
momentum. I could see a deck, but there's just so much to be gained by adding black, in the form of life gain, edicts, card draw, and additional dragons that double as removal. I'm don't know that you need the mana consistency that going mono color provides in a deck that's so focused on the mid to late game like this kind of deck would be.
Also, using fast mana to pump out creatures that require mana to be good seems a little shortsighted. You can either get them on the board quickly or deal lots of damage with them, and being able to only choose one of those options makes me hesitate a bit.