Let's assume a language once had an extensive plural system, indicating singular/dual/paucal/plural distinctions on nouns, pronouns, verbs, et cetera. Over time, as has happened in real languages, this was simplified to a simpler singular/plural system except in personal pronouns, which retained the original distinctions. In other words, the language would distinguish only between "woman" (one woman) and "women" (more than one woman), but when you used a pronoun, you'd have "she" (one woman), "she2" (two women"), "she+" (a few women), and "she++" (many women).
Your conversations would those look like the following:
- "That woman came out of the store. She is carrying a bag."
- "Those women came out of the store. She2 are carrying bags." (Two women came out)
- "Those women came out of the store. She+ are carrying bags." (More than two women came out)
- "Those women came out of the store. She++ are carrying bags." (Many women came out)
A similar situation situation would occur with all personal pronouns.
So, the question: while this sort of thing is obviously possible, since I just described it, is this a feature which has been documented in a natural language? I'm not just restricting it the way I've done, but the general situation where the grammar of the language has simplified down the grammatical number, perhaps even to not having a singular/plural distinction at all, except for retaining a more elaborate grammatical number system in one single common grammatical element.