Here is my thought.
I am not a racer, just an long time avid practicer with a couple of trucks. If what I say dosnt jive with the norm, sorry I am not sure what the norm actually is.
My trucks and bugy include.
T4, 10T, Laxer zx5, and recently sold my 3.3 revo.
Where I practice, I feel the 27t it just a waste of time. Its a good track but the 27t is slow on the straits, and it labors over the jumps. The buggies seem to be quicker but still not exciting.
On the other hand, to me, 19t is what the stock class should be. It is fast enough to be fun, competiteve, and it is controlable. If someone wishes to run a 27t in the 19 class- go for it.
Anything less than 19 should be run what you brung. If you can handle a fast truck good. If you cant keep practicing untill you can, thats how you get better.
Besides the above 2 classes, there should be.
2wd Truck, 2wd Buggy. 4wd electric, which would include both.
Same for nitro.
Just my thought. It would make the classes smaller, and there would be more drivers in each class. If the turn out for one class is to small, they can combine like classes only if the other class agrees.