This got me thinking the other day, and since off-season is coming to an end soon, I might as well ask.
After some thought, offensive minded guards who are not great defensively like Trae, Lillard, Curry etc, would be the worst at guarding themselves imo.
The best at guarding themselves in game would be great two-way wings and centers imo.
Depending on your definition of star, Gobert has the worst offensive skillset while possessing the best defensive skillset, so he’d be pretty good 1v1 mirror matchup. The most troublesome could be Kyrie or Luka, some really crafty offensive savant that mimics a traffic cone on defense.