In my opinion, calling them objective pronoun amounts to conflating the terminology with subjective or objective case. In any event, “subject” and “subject” would be used synonymously and simultaneously here, and likewise for “objective” and “object”.

I would have thought that personal pronouns are a subset of all pronouns, including I, me, you, she, her, we, us, them, who, anybody, somebody, while impersonal pronouns include it, what, something. Why do you think so? However, none of the usage notes I can find indicate that personal pronouns stand in for “grammatical persons” (I, you, him, she, them, them), as in first person singular, third person plural, etc. -while impersonal pronouns are like “One”.