Yeah sure, but him being ahead in the countries require major context, like Windies/Bangladesh just doesn't make sense considering the difference in quality of attacks, it's simply Smith being better in New Zealand, England and UAE while worse everywhere else.
Less than a year later Rabada would've an amazing series in Australia, he was just amazing right off the bat, recently he has been figuring out how to bowl in Asia and in pitches without high bounce or variable bounce (NZ/Eng), his abilitu at home and in Australia was never questionable. The 2016 attack was indeed very good, and the 2009 attack I'd argue was better than the England attack Smith feasted on.
It's definitely not close on home conditions between them on the basic law of output, and the 31 average in South Africa to me speaks more about how good south African bowling was, and especially the elephant in the room being Morne Morkel who (barring maybe Ishant) Cook struggled with the most in his entire career, in England or in South Africa. Smith averaging 68 in England is great but I always said Smith is a better player of movement so It doesn't surprise me that he performs in 2000s England.
The eras overlapped, the team qualities didn't, Taylor/Gabriel/Holder/Roach are much better bowlers to face in Windies than the ones Smith feasted upon, and 2016 Bangladesh (which brought Cook's 110 average in Ban down) were on horrible turners and against decent spinners bar pre-2014 Bangladesh wasn't international level in bowling.