This sorta seems like an obvious thing to say, but I get the sense that making it explicit is useful.

It might not be. Any further explanation is costly, and would be welcomed only if the subject is really interested in the topic. If not, you would come across as pedantic and boring.

The problem is that I feel pressure to be consistent with what I said, even though I know it's a simplification.

I think that you should learn to resist the pressure. It's very rare that someone will call you out for some inconsistency, even blatant. It's quite amazing, actually. In the rare cases where someone does call you out, you can just offer further explanation, if you care to.