Did you forget that this entire thr3ad is about a hypothetical new edition?
Subclasses do not determine whether the class is simple. The class does. Period. This derail about subclasses on the existing simple classes (and yes, they hoth do have multiple simple subclasses) is not useful on any level.
Subclasses come into play when you are using comparison and base assumptions.
Engineers are complexity scale from 1 to 10 where 1 is the most simple you can make this class work and be balanced and 10 is the most complex.
Say that we're attempting to make a simple arcane caster that is between 2 and 5 whose subclasses can increased that complexity by 1-5 points.
IMHO the base 2014 fighter and barbarian aren't the most simple classes 5th edition made, and they would be classified as a 3. The 2024 versions are more complex. And I would say that they are now a 4 and a 5 respectedly.
Then, you add subclasses. The champion and the berserker are the most simple. It's so complexity wise, they might be a one additional point of complexity. Every other subclass in the game for in all 2 classes increases complexity by 2 or more. In some cases, for a spellcaster subclass, you might be increasing complexity by 4 or 5..
My point is that if you use the simplest class plus the simplest class as the basis of what you consider simple, you're still
half way up to complexity scale.
Champion fighter is managing accident surges. Second, when uses and indomitable uses. And I forgot the inspiration points that recover every turn when you get to high level.
They didn't combine them all into one resource.
The simplest class subclass combination in 2024 and 2014 starts with
2 additional resources and gets a 3rd. And
every single other subclass for that class gives you a 4th.
You can make an arcane class that is as simple as the fighter, but IMHO i wouldn't call that class simple.