Pictures would be helpful. If you let the three fruit stay on the atemoya you will sacrifice allot of growth this
season. I have seen pictures of atemoyas that are shrub-like that you are describing. I've even seen them 15 foot tall and 20
foot wide. I have a lisa, dream, and an Australian atemoya. I trimmed the lower branches off and am trying to get a tree
shape with one main trunk. I have 4 larger and some smaller grunichama, I have noticed mine produce better each year.
I think you will do much better next year if your tree is only 4 years old and had a small amount of fruit this year. If your
grumichama is leggy with 2 main branches, you could prune both branches and make it spread out. Next year you will have
more branches = more fruit. Last year my lisa had one nice fruit on it and I yanked it. I was very happy with the growth it ended up
having. This year it is 7-8 feet and has small fruit on it. I probably will yank them again. It's hard especially since I have never eaten
the fruit. I hope patience will pay off and one day I will get 50+ fruit from my tree. I am also in 9b and want to get growth fast so
the inevitable cold night doesn't kill my tree
Mike