Here's one of your previous questions and its thread where many people answered.
I think this is a better plan for seeing the Cotswolds.
What happened to this itinerary you were planning?
https://community.ricksteves.com/travel-forum/england/question-about-the-cotswolds-england-itinerary
If you are planning to be in Oxford, then Moreton-In-Marsh is an easy train ride from there to catch the GoCotswolds tour.
You mentioned Stratford-Upon-Avon (with a question mark) in the thread, and that is also one of the places from which you can catch the GoCotswolds tour (it's their home base).
acraven is right.....GoCotswolds gives a great tour.
https://www.gocotswolds.co.uk/product/cotswolds-in-a-day/
I encourage you to share with us here your revised itinerary. If that is still in limbo, I encourage you to include Oxford and Stratford-Upon-Avon. All is not lost if you cannot get to the Cotswolds while in Bath via the Mad Max tour.