Known and described subclasses of Context-Free Grammars class
Density might be interesting concept for you. The density function is defined as
$$\delta_L(n) := |L\cap \Sigma^n|,$$

where $\Sigma^n$ denotes the set of all strings of length $n$ over $\Sigma$.

Your first language seems to have density values of only 0 and 1 while the second goes up to 3. So the first is 1-slender, the second is not following the terminology of  Lucian Ilie's work.