Significantly different parenting schedules in same household

Anyone else have significantly different parenting schedules in the same household?

For example, I have my children (4 & 8) every other week. Friday- friday. And my spouse has their child (8) 3 days every single week. Saturday- Wednesday one week, Sunday- Wednesday the next week.

About a year ago, we got SK on the same schedule my bio-kids were on- friday-friday so spouse and I had more time for activities with all of the children, spouse and I had more alone time, spouse and I could plan out-of-state trips that lasted longer than 2 days, and we could plan trips that included all of the children.

HCBM decided unanimously about a month ago that she wanted SK back on the 3 day on/3 day off schedule, and my spouse gave her what she wanted without even discussing it with me. I am still struggling to deal with the complex household routine, and the fact that my spouse made a decision that affects the entire house without discussing with me first.