I just wanted to point out a couple things here for lat development.
A few key points:
1. The lats cross the shoulder joint and also a portion attaches to the hip.
2. The superior fibers are less fast twitch than the inferior portion (and chinups, v-bar chinups target the inferior more)
3. The lats act to internally rotate the humerus.
So for number 1, what this means is you should get a good stretch in the lats when you work them, which means you have to bend at the hips at the bottom of a barbell row. This will put a good stretch on the lats.
No.2 just means make sure you don't skimp on the 5-8 rep range for building the lower lats.
No. 3 means the pronated hand position in a barbell row is better for the lats.
Give this a shot next time you do standing barbell rows. Use an approx shoulder width grip, palms facing you (pronated). Deadlift the weight up, ARCH THE BACK, and then go into the row position while keeping the back arched hard. The elbows should stay near the body, and as you lower the weight, bend at the hips, so when you are at the bottom you are bent over pretty well with your arms 98% extended. Stand on a platform if needed to do this. Don't allow the arms to fully extend as this takes tension off the lats and requires the arm flexors to get it moving again. KEEP THE BACK ARCHED this whole time, and then row the weight up, minimizing assistance from the hips. Use a slower negative portion.
This sounds complicated and honestly if all you've ever done is heave the weights around it will be at first. however once you get it down, it's simple. You'll feel your back being worked, especially the lats, a LOT more with this method vs. just heaving the weight up each rep. Make the muscles work! Don't just go for heaviest weight. This may require you to lower your normal rowing weight, but trust me you'll feel it in the lats if done right.