Good idea St John. Couple of small typos with the spelling I think
Naau - Neau Vietabia - Vietibia

And it seems like you would have to have specific pairings for each group of four countries or cities to be accepted but no logical reason why a different group of four couldn’t be put together.
Still fun trying to work it out though.

For example why couldn’t Bhuzania Tan Vietibia and Nam form a group?

Good ideas, but impossible to solve without being a mind-reader, as the pairings were arbitrary, and members of groups interchangeable. Also it should be Neau, for Nepal-Palau.
I failed to get any group despite seeing the connections within seconds. The only logical solution I saw was to group Naau Vietibia Bhuzania United Kingindica together- as groups of smashed country pairings, Harroshead, Loncaster, Blackley Reddiff - as a group of smashed town/city pairs, Pal, Tan, Dom, Nam as the links between the countries, Car, Don, Gate, Burn, as the town links, as there was no reason to put Vietibia with United Kingindica, than Bhuzania or Naau, or any reason for Loncaster not to be paired with Blackley or Reddiff instead of Harroshead.

I should add that I got all the groups ultimately but it was a bit of trial and error. The concept worked ok for me, for example putting Bhuzania and Tan together, but then there seemed to be three other possible pairings to go with that with only one accepted.

I could see what you were doing but still found it fiendish!
I think there is some definite marking down going around, would suggest
one of your other monikers ; )

Thanks for your feedback everyone, I enjoyed the idea when it came to me and apart from a mis-spell it had possibilities. It wasn't until I submitted and tried it out I saw the obvious problems you have pointed out, So all in all it's thanks and back to the drawing board :-)

...and PS, I think the mark for this effort is fair

It still gets a thumbs up from me