Also, why is it that most XL's have the main observation site also on the 8 city?
All STARs are like this, including even a few intellistars (though it was a lot more common before HiRAD). In your case, it's likely either because 1) there aren't enough airports in the area or 2) in case you missed the data on the first CC page.
A shortage of observation sites is far from an issue up here. Surprisingly, there are a lot of airports in the northland. For example, Traverse City, Cadillac, Bellaire (between TC and Petoskey), Petoskey, Charlevoix, Gaylord, Pellston, Cheboygan, Beaver Island, Mackinac Island, Chippewa Arpt (halfway between the bridge and the soo), Sault Ste Marie municipal, Newberry, Manistique, Marquette, Escanaba... just to name a few.