They tend to name them chronologically.
But for example, if you're undiagnosed autistic or ADHD then you probably will present with anxiety, so you go to your doctor's and say hey I'm not coping, I don't understand why, I'm having several panic attacks a day, I am struggling to leave the house or do any work while I'm at work, and they say you have anxiety, possibly agoraphobia, here take these SSRIs and come back if they're not working.
So you take them, they don't work because the anxiety is distinct anxiety. You aren't anxious about things that aren't likely to happen, you're anxious about things that have happened to you, and continue happening to you.
You go back, they say here try these other medications and come back to us.
You do, you feel numb, but you're still not functioning, you struggle with executive dysfunction, you cant start tasks, finish tasks, keep track of time, you feel like you've gone from one extreme to another.
You go back. Oh it's depression, or if you're a woman, it's bipolar.
You start to question your life and do some self educating and come to the realisation you've always been like this. You think if this is ADHD, I could be medicated, and that could fix me, so you go you get your ADHD assessment, you get your medication, and it helps but it doesn't fix you. It helps you sustain attention, but you don't get to choose what it is your attention is sustained on. You realise you are still emotionally dysregulated and have communication struggles and you aren't coping with changes and you've had persisted deficits all of your life.
You go, you get an autism assessment and then you are diagnosed with autism.
Obviously I'm not saying this is the pipeline for everybody but it is for a lot of people very similar to this, and so it can look like you're collecting the alphabet, but no, it's recorded chronologically.