Hi again.
The above post has solved my problem. I was able to effortlessly pair both controllers by following those instructions. For anyone who is stuck and sees this thread, I believe it was this command that solved the problem: sudo apt install bluez=5.50-1.2~deb10u1+rpt2. After updating the packages and checking the bluetooth status, I still got the Failed error messages, but once I inputted this command they disappeared. Of course, try everything just to be safe.
Thanks for your help!