I've wondered this throughout my entire play through. Supposedly the lead voice actors for Red Dead redemption 2worked full time for ~5 years to get everything

I've wondered this throughout my entire play through. Supposedly the lead voice actors for Red Dead redemption 2worked full time for ~5 years to get everything right (assuredly with endless rework). An A-list star usually spends 6 months to a year at max recording for a movie. How much did they have to tweak just to make sure they were getting the most from the Keanu investment vs. pivoting/cutting what wasn't working?