>but how do you solve complex logic problems

If a species were (human level) intelligent, how would they have language first, if there is no need for an unintelligent species to have language (you know, other than bee booty-shaking tier language)?

It becomes chicken and egg. They don't need the language without intelligence, and can't become intelligent without the language (all so they can boot up the internal monologue that is apparently sitting there waiting on a 12,000 word vocabulary).

This is clear to me, because I don't rely on an internal monologue to think about such things. It is unimaginable to you, because you rely on an internal monologue.

Human (and animal minds to a lesser extent) do not think in a spoken language, but in an internal symbolic "language of thought". It is beneath the perception of an "internal monologue", but also tends to atrophy quite severely for people who rely on an internal monologue. Even in your brain though, there are so many different mental processes that you are unaware of for this reason. You can't even reliably sense cause-and-effect in your own mind... the internal monologue just makes up whatever plausible best guesses it can about why you made this decision or that decision, about why you did X or didn't do Y. The internal monologue doesn't have access to that other part of your brain.