Campaign Foreign units

I was just wondering are there foreign units for members of the Coalition when they conquer a region? The French had Polish and Swiss line Infantry, and I remember playing as the British I could recruit Native troops from African regions. I liked this because it gave me a feeling of conquest but as playing as a member of the Coalition I haven't found any foreign units so far.

King's German Legion units can be recruited by GB in some Germanic regions as well as some British-Dutch units too; this functionality needs to be unlocked by a mod.