“The only way to stop if from controlling the plane was to cut power to the electric motors that run the trim. “
The yoke trim button over-rides MCAS.
“The yoke trim button over-rides MCAS.”
You do not have a good understanding. The interaction between the two is way more complicated than what you think. The MCAS output comes in timed waves. During those waves then MCAS does appear to have priority. Using the Yoke buttons did not disable it. The method for disabling the MCAS also disabled the Yoke controls(As explained). If this were not the case then the plane would have never crashed.