Actually, I think you might have been better off with 4 🤔

Here's the issue complicating things, the minimum tick is 2%. With War Tax at 5%, each tick costs 300 popularity. So with four 500 cities you had four 2% ticks (per 2 hr round), and now with 1000 you have two 3% ticks.

My new model has 2400 popularity with 8% per tick, giving it really nice distribution even in moderately heavy wartimes.