Marrying someone with opposite traits gives us a chance to expand and grow ourselves. Planners have the opportunity to learn to chill a little and non-planners can learn to appreciate the stability that even a simple plan (or basic vacation packing list, lol) can offer. Instead of looking at it as a conflict, consider it an opportunity!!

+1
I've observed that it's rare that two non-planners marry (or are partnered), or that two planners marry. LOL! It's usually one of each. All the better to learn...
My DH is an obsessive planner although he's mellowed. He has daily, weekly, monthly, yearly, 5-year, 10-year, etc., plans.

I, on the other hand, am pretty much a go-with-the-flow kinda gal for the most part. I have learned though, to make plans for certain things and voila! It is quite interesting to see how life unfolds according to The Plan. Sometimes, it just doesn't—we can make a plan then life goes sideways.

That stresses DH out, and does not stress me out.
My parents are wicked about making decisions while "the kids" are home. Example:
Me: Mom, what would you and Dad like to do today?
Mom: Well, anything, dear. Anything that you kids would like to do.
Dad: Whatever makes you happy.
Me: Do you want to go to visit _____?
Mom: Whatever you'd like.
Me: When would you like to go?
Mom: Whenever suits you, dear.
All this above talking goes on, yet no decisions get made. One visit, my DH was getting super-stressed about sitting around waiting for a decision to be made. After pretty much a day went by with the aforementioned nonsensical conversation, DH took me aside and said, "You know, it's okay if we sit around and do nothing, as long as we *plan* to sit around and do nothing." I confess that I burst out laughing! That comment has been a standard joke between us, ever since. LOL!
Between the two of them, my mom is a total list-maker! She has lists for everything and everyone. I suspect that's partially why I was so reluctant to make lists.
His folks? Many, many, many lists of things to do each day, with little "tick boxes" to check off the things that were accomplished that day.
Somehow, I like to think there's a happy medium in there somewhere. After nearly 20 years' marriage, we are pretty much there. I've learned to plan, (a bit) and DH has learned to chill. A bit. LOL!
