Certainly a productive tree and I can imagine a single tree that might be that productive, but there is no way to manage and harvest a hectare of 16m trees, and that spacing would be tight/shady (if I am picturing that right in my head). A 16m tree is big...
Jackfruit would have to be up there for production.
Haha, not saying that would be a practical cultivation approach, by any means; I'm just trying to assess species productivity.
I had to go in and plot it out and I think you may be right on spacing. From re-looking at pictures and measuring, I'd say that no more than 1,5x taller than wide is more typical for old giants (young/grafted trees are closer to 1:1). With that plotted out, 1,3x their height apart looks too tight; 1x looks a lot sunnier. Could also envision it as rows, so 16mx10,6m trees, 10,6m between trees, 24m between rows - a giant scale equivalent of an orchard of 3x2m trees with 4,5m row spacing. Works out to 35t/ha typical and 105t/ha record. Even if you assume that it was in the middle of a field and nothing ever cast any shadow on it whatsoever, and you assume that a plantation of them spaced out as above loses 1/3rd of its productivity to shading... still very impressive figures. And in commercial cultivation you expect a lot more careful optimization of feeding, watering, etc, which generally has a very significant impact on productivity.
2,7 tonnes of fruit... that's something like 18k individual fruits from one tree. Just mind blowing!
Don't think I've gotten to artocarpus species yet, but I strongly suspect you're right on that.
ED: Re, jackfruit:
http://www.ccsenet.org/journal/index.php/jas/article/download/52258/28457"The whole population was divided into two subpopulations (high-yielding orchards and low-yielding orchards)
on the basis of yield: high-yielding orchards in which fruit yield were equal or exceeded 90 t/ha, and
low-yielding orchards in which fruit yield were lower than 60 t/ha. "
Those are figures from high intensity cultivation in China; I suspect you won't find numbers that good in the less high intensity cultivation in many other tropical locales. But still... some species just have great genetics. If only mangosteen could take a cue from them...