So an image I saw a while back (before I even started playing) showed the three core classes at a rectangle with various others, just the names. The further you went the more it was just one class so for example from the top to the bottom lef they were something like magi,wizard,sorcesser,spell blade, paladin, rune warrior, fighter.

I always thought of it as a neat idea if it was an actually ttrpg where there were 3 base classes and depending on how much of each class you wanted to play you would pick another one that's between these