Much of the different specifications for the same car (in different parts of the world) have to do with the varying base oils supplies around the world.
About 65% of the world Group II base oil production is here in North America -- and we use most of that capacity in our oil market. Another ~ 30% of GII production is in Asia Pacific (mostly Korea, S-oil and S.K.). This means that the vast majority of conventional motor oils outside N.A. are Group I based. There is no way to meet the latest specifications for the thinner motor oils like 5W-20, 5w30 and 10w30 with Group I base stocks. So, you either end up with heavier weight Group I oils like 15w40 or 20W-50 -- or perhaps a 10W-40 based oil that has older specifications (1990's) like SJ.
The auto manufacturers have to specify what is readily available, so, outside NA one either specifies synthetic, or a heavier conventional Group I based oil. You want as robust a Group I as possible and the 15W and 20W oils can use heavier weight base oils because they don't have to meet as stringent cold properties as the lower W's. This would particularly be the case in many of the warmer climates (Australia, most of South America) -- where they don't really need 5W or even 10W oils, so there has been no push to the thinner oils. They just use the heavier Group I based oils or synthetics. Europe has the same problem, they didn't invest in Group II plants so they either use the heavier Group I's or specify synthetics for longer drains to mitigate the costs and get higher quality oils.
There are likely some Group II/II+ (5W-20, 5w30, 10w30) SM/GF-4 rated oils outside NA, but probably not very many. Specifying a 5w30 in a place like Australia would put the mainstream consumer in the position of having to buy synthetic based oils which are quite expensive (compared to the prices we pay here in NA!). If faced with using a 10w30 or 20W- 50 Group I in a "tropical" climate, the heavier oil will take precedence over the lighter one (the fuel economy benefits of a 20 or 30 wt. over the 40-50 wt won't be as great in a warmer climate and don't outweigh using a heavier oil).
We have it good here in NA -- conventional oil "heaven".
We get "high-performance" Group II motor oils at about the same cost structure as what Group I based oils would cost.