Many individual components are made under contract, and the newer the Harley, the more likely these will be imported. Things like brake calipers, ignition modules, gauges, etc.
Mine is a '92, it has very few metric components, and I keep the appropriate wrenches in the toolbag.
10mm, 12mm, and 13mm are all I've ever needed on the road.
The nut on the starter's positive terminal is 13mm. 1/2" is too small, 9/16" is too big, and there's no room for an adjustable wrench.