Okayama and takamatsu?

Hey folks, I wil be spending a good time in kyushu in december but going from fukoka to okayama / takamatsu. I have been to hiroshima and miyajima before and have a question

Does it make sense to stay 3 days in okayama then 3 days in takamatsu or 5/6 days in okayama then day trip or allocate these days else where ?

Okayama (3 Days)
Day 1: City & Castle. Korakuen Garden and Okayama Castle (combo ticket). Afternoon at Saijo Inari for the torii gates. Dinner: Barazushi and Oyster Okonomiyaki.
Day 2: Kurashiki Day Trip. Full day at the Bikan Historical Quarter. Canal boat ride, Denim Street, and walking the preserved district.
Day 3: Nature/Views.
Either: Kibitsu Shrine (renting bikes for the Kibi Plain).
Or: Bitchu Matsuyama Castle for the mountain views.

Takamatsu (3 Days)
Day 1: Gardens & Udon. Ritsurin Garden (boat ride). Spending the rest of the day udon hopping (Udon Bou or Nakanoya) and Takamatsu Castle ruins.

Dinner at Ikkaku for Honetsuki tori (bone-in chicken).

Day 2: Ogijima (Cat Island). Ferry to Ogijima for the lighthouse hike, art installations, and cats.

Day 3: Island vs Culture.
Either: Shodoshima Ferry (Olive Park + Kankakei Gorge).
Or: Shikoku Mura Village + Yashi

I feel there is good activities in both but idk if my itinerary makes sense or what wouls you recommend?

by Might_Time