The key thing is that you have noble blood. It doesn't matter how stirring a speech a commoner is able to deliver: he's still a commoner.
I think we agree more than we don't. A commoner is indeed nothing but a commoner, one that is
not equal to a noble. But I do wonder if you're side-stepping the actual issue that was raised (namely that nobles are related to commoners), and that noble families came from somewhere.
It doesn't matter if BM says "all new noble families are just those that weren't prominent before"
(though this is the first time I've heard this -- are we restricting people's RP of their family founding now???), it still had to come from somewhere.
And people
were given noble titles for their deeds. As I mentioned, nobility was by blood or deed. Either way, your Superiority was "recognized".
Now granted some societies historically did care about how "pure" a noble's blood was. Some knight organizations required that you trace your noble lineage for for x-number of generations. But that just determined how far back you went... it was understood if you go back far it eventually stopped.
