The idea of corporations being legal people is questionable in the first place, but now you’re going to argue that they’re not only people but citizens?!
Plenty of rights are conferred by merely being within the borders of a country, regardless of citizenship status. You can be a tourist or even an illegal immigrant in the US and have the right to habeas corpus or the right of non-self-incrimination, for example.
Talking about elevating corporations to be on par with citizens is a fascist idea, which is absolutely adjacent to corporatism.
A key tenet of fascism is protecting corporate interest and power... but okay.