Many lifters skip unilateral exercises for their lats. That's a mistake. Single-side exercises allow you to bypass the bilateral deficit and give you a unique stimulus.
Now, the one-arm chin-up is probably out of reach for most lifters, but you can still reap the benefits of unilateral training with this challenging exercise:
These allow you to overload the eccentric/negative contraction of the lats. Do them enough and you'll be able to do a one-arm pull-up as well.
If you can't do 2/1 pull-ups yet, you can do this variation:
Add these to your program and get ready for some balanced new growth!