How to pipe output of command to two separate commands and store outputs

I have a really long command that runs over a huge file and I am forced to run it twice which doubles the time it takes to run. This is what I am doing at the moment:

x=$(command | sort -u)
y=$(command | sort -n)

I was wondering whether there is any way to redirect the output of command to both

-u

and

-n

and store output of each into separate variables or files like I did above with

and

. I tried to use tee to do the following but no luck:

command | tee >(sort -n > x.txt) >(sort -u > y.txt)

I tried to redirect output to text files but it just printed it to standard output instead. Any tips or ideas?