These 7 plus 2’s are a great testing tool. If you want to shoot at a high level, you should be able to do at least 8 reps. If you can do fewer than this, it is not impossible for you to shoot to a high level, but it will be much harder.
Bow training exercises like 7 plus 2’s are great to help you control your bow. However, you should combine these with general exercises you do in the gym. See our dedicated page: Recurve Archery Exercises.