Unless the event card changes our vault size, I propose that we substitute the first match in round 10 (and if we lose the first, we should substitute the second match as well). Our current vault is 96, which results in us fielding two decks. If we playing both matches without substituting, our vault size will be
exactly divisible by 36 regardless of match outcomes.
win both: 96 + 12 = 108 = (3 * 36)win one: 96 + 6 - 30 = 72 = (2 * 36)win zero: 96 - 60 = 36
Basically, we should not salvage 6 cards for the first win of the round.
We can actually field competitive decks the rest of the way regardless of what we choose to do here. Our vault has 4 steals, the earth duo cards, a fractal deck, and we can salvage lots of juicy aether and fire cards from our Round 9 aether opponents' decks. However, for these same reasons we do not need any salvage from opposing decks. Salvaging is +6 cards, but every deck we field has an EV of approx -12 cards.
Just my two
.