I will post testing results for your benefit later on. Theory is all well and good but completely meaningless without results. When I say 30% to win it's based on experience with the decks (I have already tested them some) and especially with the deck our team built. In the matches, Hyroen drew 3 pendulums both games he won and got an instantaneous and permanent wall. If your concept is that that would happen 60% of the time, you are mistaken. It's not really relevant to what actually happened what marks the players have -- Hyroen had Wings up on turn 2 both games that he won. And if he only gets them on turn 3, he also loses because Scorpions have hit him at least twice (assuming no Discord). It's a lose-lose and the only reason you have the impression it was close is that the Wings went up as fast as possible.
In a nutshell, in this matchup Hyroen has absolutely no way to survive unless four things happen, in this order:
1) Zeru does not get Discord out early. If this happens, Wings won't go up for about 5 turns and Hyroen will have taken 40 damage and have 10+ poison.
2) Hyroen gets Wings up instantly. This can only happen with 3 pendulums being drawn out of 9 on the first turn.
3) Hyroen gets Fahrenheit up early. If Fahrenheit is late, not enough damage is dealt to Zeru before neurotoxin kills Hyroen. Even if everything else goes perfectly, he needs Fahrenheit early and there are only 2 in the deck.
4) Hyroen has enough Wings to keep them up indefinitely. It's not unlikely to have Wings in hand when you've got 6 in the deck, but it's actually not that unlikely that over 15 turns you get a slightly bad draw and don't have Wings. Well, a single turn without Wings against a bunch of 6 / 6 or 8 / 8 Scorpions means certain death.
Literally a single turn missed and Hyroen dies. 30% is probably a high estimate of his deck's win probability in a single game.
If we assume the probability of a deck to win is 30% in 1v1, then the probability to win 2-of-3 is:
(0.7 * 0.3 * 0.3) * 2 + (0.3 * 0.3) = 21.6 %