Dogo Aregentino's (DA) are popular in Europe and South America. When I was in Europe about 10 years ago I noticed that they are a massive breed and should be handled by experienced owners only. But that goes for a lot of breeds. Wobbly - I know you have already addressed this but I am surprised you met the dog at its level, especially a DA. I never would advise this. These dogs are common in Spain and Italy and are found on country / rural properties such as farms and don't warm up to any stranger in a hurry.
I doubt of many in AUS and NZ, (I have never seen one of these or Presa Canario in Aus) as they are usually American Bulldogs, misjudged as DA.
Still, a very striking and confident breed. No mucking around there.