The lats are a really important muscle group to get strong if your goal is maximizing club head speed. Especially the lat on the lead side.
Why? They are a very big & strong muscle group that play a big contribution when we swing our arms.
This is one of my favorite exercise options to train them.
Something like 2-4 sets of 5-8 reps each side works great.
Train muscle groups 2-3 x week.