In my experience the most important thing is what is behind switch. Do you have round or square boxes in you wall or you just have rounded hole in it. As you know we in europe usually have switches with two hooks that are screwed into the wall to hold switch in place. Something like this
So the first thing will be to check how your switches are mounted into the wall.
I have rounded hole in wall for switch to be mounted. In my experience the best switches for this is bseed brand as it has metal plate. So when you mounted it in the wall switch frame will not bend.
Some other switches like moes have plastic frame and can easily be bend and it is hard to turn off on light in that case as switch takes a bit of force to engage.
I will try bseed with a metal plate. Most of my switches are zigbee bseed with metal plate as they can be easily mounted and they are very responsive on the touch.
I have double switches just like you and I used two separate switches. They did fit. You can buy one plate for two switches. I don’t know will this fit. But as I installed most of my switches they did fit. You can screw them in the wall or in the plastic box or between wall and plastic box. Just don’t use provided screws.
Maybe you will have to make room for one switch but its doable. Just make hole little bigger on the bottom.
Every switch is around 8.6 cm. This is outer dimension. Dimension of the switch mounted on a metal plate is around 1 cm less.