Toughest 70.3? What about Braveheart?!
These are really useful scoring systems to help us chose races. But you missed a newish niche race, the Ben Nevis Braveheart Extreme Triathlon. It starts in a sea Loch (Loch Linnhe) beside Fort William in Scotland (12c), then you bike into the Highlands (660m ascents), then you run up and down the highest mountain in the UK, Ben Nevis, 1370m in ascents. Mean time race time is 7hrs 30mins. An epic race in a beautiful and savage land. I think that would land it in the top 4 on this article.