Yeah, I work with an English second language guy who uses pronouns excessively, leaving me clueless. In his case I expect he's saving processing power for translating the bigger ideas.
Pronouns in some languages are less confusing than in others, he might be coming from a language where pronoun-heavy sentences are clear.
One feature of language that helps with this is gendered nouns. In English "a book lies on a table, destroy it" can mean 2 things. In some languages you use "her" or "him" or "it" depending on the grammatical gender of the noun even if it's not a person. If the table happens to be male and book - female - it's clear what you meant.
