So what's up with all the "Sulla discovers breaking flaw" threads everytime he posts a report? I thought it was widely known that more cities are always beneficial, and I certainly remember a thread about the Forbidden Palace in combination with Planned Economy. It almost sounds like you have some personal issue with the game
For the record, part of the problem is the stupid AI again. It's very rare than an immortal AI in the position that Hiawatha is in this game doesn't have enough gold to buy enough city states to sabotage a diplomatic victory, but they don't seem to do that. AI on higher difficulty levels is
no trouble at all unless they absolutely have to expand into your territory.
Btw., Forbidden Palace+Planned Economy is only powerful for medium-smallish empires. The more citizens you have, the less the impact of the lack of unhappiness from number of cities. This is why Gandhi's UA is so powerful, too. Nothing of what Sulla does in this game is broken by itself; the problem is more
why he wants to play as he does. For example, science being based directly on your number of citizens is a strong incentive to have a large population, but there is no cost associated with it if you know what you're doing.