Well, somehow the entire sheet has to go down. And then out of the building. That's why bathrooms are usually planned on top of each other, so the toilets have a short outlet. If the architect has planned this in the top left, then you can't just put your toilet in the bottom right. Somewhere, the pipe(s) have to run with a 3% slope.
If you put the sauna under the slope, you have more options with the other things.
I can't understand why the toilet shouldn't be by the window or how a staged shower can also be a great eye-catcher when you come in. But yes: with kids, it's probably not so great :cool: