Personally I wouldn't be messing with extra wide bench exercises, too much stress on the shoulder for my liking.
A good way to get those pullups going is cluster sets, like you have here. Except I would do clusters of 1 the entire time and maybe do 3-4 clusters per set (so 3-4 total reps per set) and keep doing sets until you've reached some sort of target or until you're ability has dropped.
Just my 2 cents.
