Whitmer is the governor of Michigan, so why would Wisconsin #s matter? She's very popular in Michigan.
Name recognition poll. No one knows who Duckworth, Demmings, CCM, or Whitmer (minus Michiganders) are.
I don't have data to back this up but I suspect people are much more likely to know who Whitmer is considering 1) how much attention Michigan/Detroit has gotten for being a rona hotspot and 2) the fact that she was called out multiple times (although not by name, lol) by Turmp.
That would be especially true if you're a Sconnie. They don't share a major media market but they share a border and are part of the same region. I don't expect Arizonans to know Whitmer that much better than the average governor but people in Wisconsin? Oh yeah.