On the topic of parses/class difficulty, help me with the following thought experiment:

Imagine two almost identical classes A and B. With both classes the real test of skill is being able to use Ability 10, which you can only do if you perfectly manage cooldowns, DOTs, etc. However, in class A Ability 10 does 500 damage and in B it only does 400 damage. Doesn't Class A therefore appear more difficult on the parses (higher skill ceiling) even though A and B are equally difficult to execute optimally? With A simply having a higher reward for optimal play (granted that might be how you define difficulty, but that seems like more of a tuning issue than a mechanics one--the classes play identically in this hypothetical)?