You could probably take out a sundial or a hourglass for a Silurian Dragon for more speed, but at the same time you lose a turn of stalling and drawing power. I also didn't know about the Massive dragon cost reduction and just figured the Titan was more cost efficient, plus free momentum, but it runs the chance of getting stolen or exploded. At the same time you could put in a(n) Flying/Animate Weapon to use just before blitzing or to be used if you think the opponent has either of the two.