The last few times I’ve played as Bengalis, I would build 4th and 5th Town Centers late in the Castle Age or on the way to Imperial Age, just to get 10 extra Villagers.
But after giving it some thought, it doesn’t seem like a great idea.
According to the State of the Ladder, Town Centers don’t pay for themselves until 10 minutes after they’re built.
With Imperial Age research taking three minutes, even with the free Villagers, Bengalis would be at a resource disadvantage if they built Town Centers after researching Imperial Age.
I also don’t feel comfortable building a 4th Town Center too early unless I have complete control in the Feudal Age.
As Bengalis, I also want to get Monks and Siege out as quickly as possible to get an impenetrable defense.