For your original list I'd add these names:
Australia: McDermott, Gillespie
England: Botham, Barnes (he wasn't a spinner)
South Africa: Ntini
Mortaza, Malinga, Nissar, Asif, Akhtar and Streak just seem to be there to make up the numbers for their countries. A great should be considered great no matter what team he played for. If they're on this list you have to assume they would have been a great even if they played for West Indies in the 80s, or at least been next in line after Marshall, Croft, Garner and Holding.