Earlier quoted context omitted.
Its harder to sue the government than you might think, see for example: https://en.wikipedia.org/wiki/Sovereign_immunity_in_the_Unit...
Regardless, the argument there isn't that you can't sue the government at all, but instead that the government is granted immunity for some subset of actions. Going back to the original point, personhood is clearly not a requirement for being named in a suit. For more examples you can also see in rem cases, where the government sues property itself for civil forfeiture. 11 1/4 Dozen Packages of Articles Labeled in Pa…
It's actually the opposite. You can only sue the government when they explicitly give you permission.
https://en.wikipedia.org/wiki/Sovereign_immunity_in_the_Unit...