Like Wolfie said, the Vecna pieces are what you should take out to add more ramp. You likely could play 10 games with this deck and never get all 3 pieces in your hand or if you play a piece down it is removed before you have all three. MAYBE if you had more ways to tutor for artifacts you need to consistently get all three, that would be something, but I feel like that's a totally different deck.
For the record, I love the idea, I like the idea of Varina and Vecna wreaking
havoc, it just seems like it would be tough to run in a moderate+ power game. But fun level looks very high in lower powered games!