They didn't get married at the ball. I don't know. Here is a more detailed picture of the motor strip , showing what is sometimes called the motor homunculus , which is a depiction of how motor functions are localized along the motor strip. The portion adjacent to Broca's area controls the face and mouth. Perhaps a neural architecture evolved for creating and storing complex motor plans has been pressed into service to create and store symbolic rather than purely motoric structures.
Evolution makes do with what it has at hand.
The structures which language recruited to its new tasks came to serve under protest, so to speak. Many of the structural peculiarities of language, its quasi-universals, and the way that it is organized within the brain no doubt reflect this preexisting scaffolding. Wernicke's aphasia is sometimes called sensory aphasia or fluent aphasia. The patient in the passage below is trying to describe a picture of a child taking a cookie. This and this and this and this.