Chaos had only lightning... and not always does he poison 6 out of 7 units :D It's not about who wins, it's just that this was one of the few cases where Armageddon was used without BPD and fire immunity.
In my opinion, Minotaurs are not needed for breaking through (or in general) (unless it's a pair of Minotaurs with double strike, so that the Lizardman bites, but that's not about breaking through).
Yes, Harpies + Chaos is my choice, but nothing prevents you from carrying a pack of Furies and putting them into battle only when it's safe.