Is it possible to paint multiple meshes at once using vertex painting?

Hey, I’m currently trying to make a floor for my project level. As the level isn’t square-like, the floor is very uneven from time to time and I have had to form the floor using multiple geometry boxes with different angles. I was gonna apply a material to design the floor, but it hit me that it won’t really work out as the floor consists of different boxes and if I would add an oak wood texture for instance, the wood boards would be cut off after each square, making everything ugly and unrealistic.

I did some research today hoping to find something that solves my problem, and I found this trick called vertex painting. I experimented a bit with it today, but it seems as well like it only works on one mesh at a time when I tried it out or it will look really broken.

Is it possible to somehow vertex paint multiple meshes at the same time, as if it would be only one big uneven mesh? Or are there any other ways to make/design a neat floor that’s uneven?

Big thanks in advance!

Edit: Did some more research and ended up on Blender tutorials. Is it worth learning and do you usually use Blender to create simple custom meshes such as a floor, wall etc?