True, it is an important difference. But the other point I was trying to make (which people still haven't seemed to grasp) is that D&D's class system isn't the right system for representing warlords and evil stepmothers. They are better represented by things like backstory, alignment, and roleplay.
I don't know why this is so hard to understand, but asking why the warlord or evil stepmother isn't a class is, to me, like asking why "plate mail" isn't a class. It's like saying, "Why isn't there a Fighter alignment? I want to play a Fighter!" Well, you can play a Fighter, it's just that Fighter isn't an alignment. And you can play a Warlord, it's just that Warlord isn't a class.
You might say, "But Warlord was a class at one time!" Yeah, well, so was Elf. It doesn't make it right.