Biology is pretty notorious for most stuff being arbitrary. There is no model. People who say there's a model, they're talking about something else - sometimes, a literal Platonic ideal of biology, that makes for an appealing pop science course, but not knowledge that like, helps you design experiments or better use drugs or whatever.
From the article:
> It was hard to get through a sentence without having to consult Wikipedia. In immunology in particular the nomenclature is expansive.
This is a common refrain. "Paternal allo-antigens" for example, straight from the literature: people who do immunology research know what that means, they do not get tripped up like this author does.
Programming computers and being good at math does not prepare you at all for understanding this stuff! Watson and Crick were not math savants. They did not have natural gifts.