It looks like at least in the pine split all 3 daughter species are in Subsection Ponderosae.
More broadly there are a couple issues here. The main one that can be addressed at all at the moment is that creating infrageneric taxonomy for the large genera that really need them is a ton of work. There often aren’t global sources for the entire genus so you have to patch together the taxonomies of different papers and floras from different regions. Some regions haven’t been updated for decades so they use old subgenus/section names and it doesn’t work, and then progress in putting it in iNat stalls for years due to lack of clarity on how to move forwards. And then if you do finally settle on a system, you have to manually move all the hundreds of species into their categories one by one. It’s just really tedious and low priority curation work. Fortunately the bulk of the work has been done for a lot of popular genera.
The second issue is a practical iNat functionality barrier; if similar species get put by taxonomists into different bins instead of together (e.g. like these situations) then there isn’t a way in the iNat system for curators to make a group that keeps them together while also having them apart.