Each region needs to have a "proxy" manager to take care of the employees within that region. As we had Canadians and folks from London with us at the time of the acquisition, we were set-up respectively.
We hired an excellent engineer out of Germany before we were clear on the processes, and it's added a significant amount of time to getting him into the the swing of things.
To avoid this discomfort, we're narrowing the region.
Hopefully, this is something that will ease in the future - it stings every time we have to turn away someone potentially brilliant from places like Brazil or Israel.
For your edit: The former is correct. Anyone with the right to work in/through the UK. You can work _from_ anywhere you'd like! I prefer at home in my jammies.