I decided to try a little experiment!
On the newest world, Neos, all income is reversed. That is, the poorest countries will receive the income of the richest countries, and vice versa.
If you stay too small, you have less sectors available to remain in the game. Each unit can only have so much power, so being too small has significant drawbacks. However, if you grow too large, you'll have less and less income to use to expand. Your maintenance costs alone will likely drop your income down to zero.
Please feel free to share any feedback you may have!