I've noticed that scaling the scene using the scene unit feature will not work on cameras, even new created ones. So If I change my scene units from metric 1 to metric 0.01 now cameras need to have a sensor of 350mm and a lens of 500mm instead of the 35mm sensor and 50mm lens, so that the DOF works with the F stops. Also if the clipping says 10m it's actually 1m. In the end other problems related to scale also happen. My rig is somewhat complicated to scale without other problems so I should've checked the scale in the beginning. Any suggestions?
The unit scale only affects the view of the scene, not the actually scale of the scene.
Meaning this value is used to model objects of microscopic or astronomical size, 0.01 being 100th of a meter, 1cm.
When in orthographic front, side or top view the grid will show smaller increments, whereas the perspective view will still show as meter units, this I think is where the confusion is with the clipping value you mention.
It's very rare for most Blender users to adjust this value, it is there for users of very specific needs.