I actually based it off of my deck, and SLOWED IT DOWN
FGs play by different rules.
12 Explosions give a high chance of 2-3 in the opening hand. With all the fire generation,they can blow up half your permanents in the first few turns, along with a hardcore spam of ash eaters and minor phoenixes. The deck works too fast (maybe not in your testing, but the triple mark, double draws, and double hp may be more significant in this case than you think)