rethinking broad beans

A small broad bean harvest from the kitchen - enough to go in a bowl of soup.

A good article on broad beans -

https://www.organicgardener.com.au/blogs/broad-bean-season

I have been pondering broad beans because I left a few of them in the garden to hold down soil and see how they would go, expecting them to wither away. We have had an unseasonably mild summer start here, but strangely they have flourished - they have grown and podded well. (They are also completely effortless and need no looking after at all).

This success surprised me when I put it alongside the conventional idea that legumes and broad beans are a winter crop. But then rethinking my childhood, there were summer lupins everywhere, which are another Fabaceae.

Here's a page on lupins -

http://urbantomato.ca/saving-lupin-seed/

It turns out that Western Australia is pretty big in lupins -

https://www.agric.wa.gov.au/crops/grains/lupins

and there is [was?] a lupin trial site not far from where I remembered seeing them riding to school in the 1980s. Apparently these were feral escapees from the programme.

So my speculation is - perhaps broad beans are not a 'winter crop' in any intrinsic sense, but only in the sense that there are better things to grow in summer, and the broad bean will recharge the soil in winter as a nitrogen-restorer. So is there is no intrinsic 'winter' quality to them, but only a (northern European) intelligent trade off that makes no sense/is worth rethinking in hoc loco?

Any thoughts?