I don't think you understand in having and maintaining good productive teams.
An Anime that are 100+ episodes will be too costly for the animator to maintain good Animation Quality, cause this will take decades to finish the series until the the manga artist ended.
So even Studio Pierrot have the best animator on their team, regardless they can't finish off the remaining of the series cause then it'll go bankrupt, and even more Budget Wise if going on Hiatus.
Adding Fillers not only to prevent from catching up to the manga, but also invest more money and some which can be more enjoyable and more improvement to the overall series.
So the only best option is to choose really important fights so that the Best Animator can handle the job.