You can attempt to, but I'm pretty sure there will almost always be at least one piece of the uniform which will conflict with another uniform in some way.
I know it's definitely possible with uniforms who share the same trousers but shako's and other helmets are a bit tricky.
Let's say you remove the white coldstream_pants which both the British Guards, British Marines and the Prussian Sappers use.
These three uniforms are now without proper legs, however when you add which ever pants you'd like them to have to the body of the before mentioned units,
they will appear with your desired leg-pieces and this will make it so the trousers are unique to the body.
In short: If you remove the original pants and glue the pants to the matching body, the pants will be unique to the body.
This can also go the other way around but I don't recommend it as it will create monstrosities.
Sorry if you have any trouble understanding it, I don't have enough braincells to come up with a better way of explaining this.
There's probably another way of doing this but it'll probably have something to do with either code or something complicated.