Why is Yayoi predicting that the god guy will send 2 shikigamis to fight each of the graduates? Wouldn't it be better for him to attack just one or two to break the star formation by overwhelming the graduates with higher numbers? He could also just send all the shikigamis to attack one graduate at a time and just attack the graduates one after another instead of all at once.
thats not really how it works, for instance don peri chan and high priest dont give a shit about numbers, its possible that even if all 12 were sent against the high priest or asura they could still get wiped out, the high priest because of his AoE go to hell curse and the asura because hes that badass and steals power
and even if it can work where they could collapse the star one at a time, hes taking a lot of damage from the other points and it means they can get weakened down from AoE curses at each point reducing the odds of a clean sweep, so yayoi assumes hell prioritize the quicker method