It's not a coincidence because they adopted their initial constitutions at around the same time or based them on the existing states that had. But we're talking about the electoral college and none of the states use something equivalent to that to choose their governor.

Using score voting instead of FPTP for state-level offices would be a straightforward legislative change in many states and still not require any change to the US Constitution even in the states where it would require a change to the state constitution, which is generally a much lower bar to overcome than a federal constitutional amendment.