Advanced plan for bottom row

[zedmango]

I don't understand how the advanced plan for the bottom row works - I have completed the bottom row, but it's not letting me take the plan.

[Komandor Tarkin]

After an estate has fulfilled city plan, it cannot be used to fulfill other city plan. If you used some estates in bottom row to fulfill other city plans, you will not be able to finish game

[bradyguy]

When you hover your mouse over the city plan, it will TELL you that you may NOT use estates from other city plans to fulfil this other one...

Usually, it's the corners, right???