Maximum Food in one city and what can it support

I haven't built this city, but this is the biggest (or very close to the biggest) they get:

• Forty Level 10 farms (5,500 food each for total of 220,000 food)
• Research Level 10 agriculture (100% base food increase)
• Hero Mayor with 150 politics (150% increase based on Base)
• 100 providence
• A Level 10 Town Hall (with ten Level 10 lakes) 35% base increase (total of 350% increase)
• 25% Agriculture Buff bonus

220,000 + 330,000 + 220,000 + 770,000 + 55,000 + 100 1,595,100 food

Self-sufficient support for :

• 531,700 warriors
• or 265,850 pike-men
• or 177,233 archers and 1 warrior
• or 227,871 swords
• or 88,616 cavalry and 4 warriors
• or 44,308 cataphracts and 4 warriors
• or 31,902 ballista

Wait...

That's not very many ballistas. I'm fairly certain that 531,700 warriors can kill any of those others (except archers of course)

That's a fault in the food math...